Motor Rebuild Suggestions
03-01-2007, 09:32 AM
#1
Burning Brakes
Thread Starter
Member Since: Jan 2005
Location: Leavenworth Washington
Posts: 768
Likes: 0
Received 0 Likes
on
0 Posts
Motor Rebuild Suggestions
Going to rebuild my 65 non-numbers matching 327 into a SHP clone. (I know – crate motor. But the reason I bought the car in the first place was to have a project my son and I could wrench on so this is part of it) It will have the 461 alum intake, 2818-1 Holley, stock alum valve covers, stock 2½ inch exhaust manifold, etc. I am going to take advantage of newer head technology and use World Sportsman II 64cc with 200cc runner heads. Flat head pistons for around a 10.2:1 compression ratio to drive on pump gas. Right now I am looking at a Comp Factory Muscle cam ground like the L79 cam: 222/222 447/447 114LSA. There is another Comp version of this cam that is 229/236 468/462 112LSA. What I want is a solid street engine with some bone but not too much. (that kid wrenching with me wants to drive it too and I plan on letting him but in this world of automatic transmissions – he has an untrained clutch foot). What I need here are opinions. Am I going down a solid road? Totally screwed up. Better cam suggestions. Thanks for anything.
Last edited by Geek's 65; 03-01-2007 at 09:35 AM.
03-01-2007, 09:47 AM
#2
Race Director
Member Since: Jan 2002
Location: Close to DC
Posts: 14,550
Received 2,131 Likes
on
1,469 Posts
C2 of the Year Finalist - Modified 2020
The guts of you motor choice seem very solid and reliable. It's very similar to my own. I now have about 90K on my work and I don't baby it. Make sure you use a good SB book such as Volume I, How to Build Horsepower as a guide to rebuild. It's published by SA Design and David Vizard is well respected in SB rebuilds either stock or HP. I took my time, made a daily list of things to accomplish and it took me about two weeks. Not sure of your tools, but a high quality torque wrench is a must. 
Dennis
Dennis
03-01-2007, 10:17 AM
#3
Safety Car
Member Since: Apr 2001
Location: Middleboro/Boston MA
Posts: 3,574
Likes: 0
Received 0 Likes
on
0 Posts
Put those cams into the Engine Analyzer program for comparison.
Seriously consider a solid over a hyd. cam, for even better performance.
Seriously consider a solid over a hyd. cam, for even better performance.
03-01-2007, 10:54 AM
#5
Melting Slicks
200cc runners on the heads may kill your low end torque. I'd suggest 180 or less unless you're going to spend a lot of time at high RPM.
Other than that, I think you're doing something cool. It is exactly what I did. Was it the most economical thing? Is it the fastest thing? No and No.
It was really interesting and challening and I learned a lot. Plus, I now have an "old school" motor that is rock solid and best if all, I have the satisfaction of knowing that I did it myself.
I'd recommend solid lifters - they've been getting a bad rep. on this forum lately but it will add to the old school feel of the motor.
Brian
Other than that, I think you're doing something cool. It is exactly what I did. Was it the most economical thing? Is it the fastest thing? No and No.
It was really interesting and challening and I learned a lot. Plus, I now have an "old school" motor that is rock solid and best if all, I have the satisfaction of knowing that I did it myself.
I'd recommend solid lifters - they've been getting a bad rep. on this forum lately but it will add to the old school feel of the motor.
Brian
03-01-2007, 04:30 PM
#6
Team Owner
Member Since: Oct 2000
Location: Washington Michigan
Posts: 38,899
Received 1,859 Likes
on
1,102 Posts
The L-79 cam is still available from GM under P/N 12364050 (kit with lifters), and from Federal-Mogul/Speed-Pro as #KC-179R (kit with lifters).
Uses plain ordinary "grocery-getter" Chevy valve springs (85# closed, 190# open), P/N 3911068, or F-M/Speed-Pro #VS-677.
If you stay away from aftermarket flat-tappet cams with "Godzilla" valve springs, you won't have any cam lobe problems.
Uses plain ordinary "grocery-getter" Chevy valve springs (85# closed, 190# open), P/N 3911068, or F-M/Speed-Pro #VS-677.
If you stay away from aftermarket flat-tappet cams with "Godzilla" valve springs, you won't have any cam lobe problems.
03-01-2007, 04:42 PM
#7
Burning Brakes
Thread Starter
Member Since: Jan 2005
Location: Leavenworth Washington
Posts: 768
Likes: 0
Received 0 Likes
on
0 Posts
Thanks to all who have taken time to look at this. Really appreciate it.
Geek
03-08-2007, 10:52 AM
#8
Advanced
Member Since: Aug 2006
Posts: 63
Likes: 0
Received 0 Likes
on
0 Posts
I agree with Brian's comment re the heads. You should be looking at 170-180cc intake ports for a street 327. I heard this, no less, from Erson, Brodix, and AFR.
Also, I think you can do better than a 40 year-old technology 350hp cam. But that doesn't mean you need to go crazy. Depending on axle ratio and compression ratio, I think something in the 210-220 range would work for you -- like this:
http://www.cranecams.com/index.php?s...31&lvl=2&prt=5
...or this: http://www.compcams.com/Technical/Se...umber=12-210-2
You'll also want to use the recommended springs. For the Crane cam above the spring P/N is 99848 with 114 lbs seat pressure @ 1.700" installed height. Open pressure @ .454" lift is prox 310 lbs. A stock low performance spring (prox 85 lbs on the seat) used with anything bigger than a stock 300hp cam will cause problems and limit your RPMs. Using Shell Rotella T or regular oil and GM EOS will ensure your cam and lifters last for 100K miles.
For an eye-opener, read this:
http://www.cranecams.com/pdf/Page608.pdf
Also, I think you can do better than a 40 year-old technology 350hp cam. But that doesn't mean you need to go crazy. Depending on axle ratio and compression ratio, I think something in the 210-220 range would work for you -- like this:
http://www.cranecams.com/index.php?s...31&lvl=2&prt=5
...or this: http://www.compcams.com/Technical/Se...umber=12-210-2
You'll also want to use the recommended springs. For the Crane cam above the spring P/N is 99848 with 114 lbs seat pressure @ 1.700" installed height. Open pressure @ .454" lift is prox 310 lbs. A stock low performance spring (prox 85 lbs on the seat) used with anything bigger than a stock 300hp cam will cause problems and limit your RPMs. Using Shell Rotella T or regular oil and GM EOS will ensure your cam and lifters last for 100K miles.
For an eye-opener, read this:
http://www.cranecams.com/pdf/Page608.pdf
03-08-2007, 12:16 PM
#9
Team Owner
Member Since: Oct 2000
Location: Washington Michigan
Posts: 38,899
Received 1,859 Likes
on
1,102 Posts
03-08-2007, 12:28 PM
#11
Tech Contributor
Good project for you both. I did the same with my son, gave him the 75 the night he graduated HS. He then built it his way.
Right now he's running a 350 with WP Sportsmans, Comp 280 magnum, Perfomer RPM, Demom 750, MDS with the 75 dist, ceramic headers,2.5 through flowmaster 40's. Hays clutch and one of my 373 differentials.
Car runs very well, although the Demon needs TLC. Has a st-10 with 2.64 1st gear. He's going to tune and bring it back to the track in the summer.
The car was in need of total mechanical overhaul when I gave it to him. we rebuild the engine, tranny, diff, steering box, suspensions, and installed new carpet that summer. He did a lot of the wrenching on it.
Good luck with your project! Keep him involved and take a lot of pictures.
Right now he's running a 350 with WP Sportsmans, Comp 280 magnum, Perfomer RPM, Demom 750, MDS with the 75 dist, ceramic headers,2.5 through flowmaster 40's. Hays clutch and one of my 373 differentials.
Car runs very well, although the Demon needs TLC. Has a st-10 with 2.64 1st gear. He's going to tune and bring it back to the track in the summer.
The car was in need of total mechanical overhaul when I gave it to him. we rebuild the engine, tranny, diff, steering box, suspensions, and installed new carpet that summer. He did a lot of the wrenching on it.
Good luck with your project! Keep him involved and take a lot of pictures.
Last edited by GTR1999; 03-08-2007 at 12:33 PM.
03-08-2007, 05:46 PM
#12
Le Mans Master
Rev Limiter
Since your son, like mine, is new to sticks, you may want to put a rev limiter in via MSD. A missed shift in a roller or solid lifter motor can cause problems. There is one in my future for my son's BB Chevelle. Jerry
03-08-2007, 06:11 PM
#13
Le Mans Master
Member Since: Mar 2005
Location: Rocklin California
Posts: 7,631
Likes: 0
Received 11 Likes
on
11 Posts
200cc runners on the heads may kill your low end torque. I'd suggest 180 or less unless you're going to spend a lot of time at high RPM.
Other than that, I think you're doing something cool. It is exactly what I did. Was it the most economical thing? Is it the fastest thing? No and No.
It was really interesting and challening and I learned a lot. Plus, I now have an "old school" motor that is rock solid and best if all, I have the satisfaction of knowing that I did it myself.
I'd recommend solid lifters - they've been getting a bad rep. on this forum lately but it will add to the old school feel of the motor.
Brian
Other than that, I think you're doing something cool. It is exactly what I did. Was it the most economical thing? Is it the fastest thing? No and No.
It was really interesting and challening and I learned a lot. Plus, I now have an "old school" motor that is rock solid and best if all, I have the satisfaction of knowing that I did it myself.
I'd recommend solid lifters - they've been getting a bad rep. on this forum lately but it will add to the old school feel of the motor.
Brian
Use 180 or even 170 runners. Much better torque.
03-09-2007, 11:34 AM
#14
I certainly don't disagree with the reasoning behind the suggestions
of smaller runners if the heads haven't already been bought...
But I'd like to point out that the 1993 Vintage LT1/350 had 195cc ports from the factory... the LS1... at 346 cubic inches.. has 205cc ports from the factory....niether of these motors suffers lack of
torque. I'm not making the argument for larger ports.. but merely stating the combination counts... and that larger ports equaling poor
torque is not always the case.. a good guide, but no set in stone rule.
Cams are "head specific"... at least when your are serious about filling the cylinders. All "Double Hump" style heads flow very flat accross the .400, .500, .600 lift range... there's just not much flow to be gained
from more lift... this is not usually the case with modern aftermarket
heads, where you are often rewarded with 10,20 or 30 more CFM at each .100 lift increment.
Putting a Double Hump cam in a motor with heads that flow differently is defeating the purpose the better heads were purchased
for in the first place.
Chevy 492's flow
.400-198cfm(int)
.500-206cfm
.600-209cfm
.... very flat.. only 11 cfm difference from .400 to .600 lift.. not much
reward at all for the increased lift.... so why not keep the lift in the
mid .400 range for ease of wear and tear on the valvetrain???
World Products Sportsman II's 200cc flow
.400- 225in/150ex
.500-240/164
.600-243/162
Benefit of putting lift into the .500 area as opposed to the .400 lift
range is 15 cfm... a theoretic 30hp @ 2hp per 1cfm of flow. Horsepower thrown away by using a Double Hump cam. CFM increase at .600 is negligable... not really worth the extra lift.
If a ground up motor was being built... the GM Performance Parts
Bowtie Vortec Small Port heads would be a good choice... they offer
decent port size with good flow.... The Bowtie Vortecs.. as opposed
to the L31 stock Vortec heads are drilled to accept either a Vortec
manifold OR a standard 1st Generation SBC manifold.
GMPP Bowtie Vortec Small Port 185cc
.400-223 cfm
.500- 251 cfm
.600- 240 cfm
good healthy flow and smaller ports... a well designed head that
should be responsive... and that also flows the cfm's to make top end.
A good choice for a 327ci sized engine.
The springs used in the GMPP LT4 "Hotcam" kit are GM part #12495494.... $37.00 from Jim Pace and are rated to .530 lift..
GM also used these springs in some of their ZZ series engines.. so they
are usable on 1st Gen SBC heads.
Closed pressure on the Hotcam springs is a cam friendly 101 lbs.
the Hotcam has .525 lift with 1.6 rockers...
For the 200cc runners to be effective they need to be filled with
air..... not partially filled... use the lift of the cam to help ensure this.
The old "Z28" springs for Double Humps have 110 lbs. closed.
of smaller runners if the heads haven't already been bought...
But I'd like to point out that the 1993 Vintage LT1/350 had 195cc ports from the factory... the LS1... at 346 cubic inches.. has 205cc ports from the factory....niether of these motors suffers lack of
torque. I'm not making the argument for larger ports.. but merely stating the combination counts... and that larger ports equaling poor
torque is not always the case.. a good guide, but no set in stone rule.
Cams are "head specific"... at least when your are serious about filling the cylinders. All "Double Hump" style heads flow very flat accross the .400, .500, .600 lift range... there's just not much flow to be gained
from more lift... this is not usually the case with modern aftermarket
heads, where you are often rewarded with 10,20 or 30 more CFM at each .100 lift increment.
Putting a Double Hump cam in a motor with heads that flow differently is defeating the purpose the better heads were purchased
for in the first place.
Chevy 492's flow
.400-198cfm(int)
.500-206cfm
.600-209cfm
.... very flat.. only 11 cfm difference from .400 to .600 lift.. not much
reward at all for the increased lift.... so why not keep the lift in the
mid .400 range for ease of wear and tear on the valvetrain???
World Products Sportsman II's 200cc flow
.400- 225in/150ex
.500-240/164
.600-243/162
Benefit of putting lift into the .500 area as opposed to the .400 lift
range is 15 cfm... a theoretic 30hp @ 2hp per 1cfm of flow. Horsepower thrown away by using a Double Hump cam. CFM increase at .600 is negligable... not really worth the extra lift.
If a ground up motor was being built... the GM Performance Parts
Bowtie Vortec Small Port heads would be a good choice... they offer
decent port size with good flow.... The Bowtie Vortecs.. as opposed
to the L31 stock Vortec heads are drilled to accept either a Vortec
manifold OR a standard 1st Generation SBC manifold.
GMPP Bowtie Vortec Small Port 185cc
.400-223 cfm
.500- 251 cfm
.600- 240 cfm
good healthy flow and smaller ports... a well designed head that
should be responsive... and that also flows the cfm's to make top end.
A good choice for a 327ci sized engine.
The springs used in the GMPP LT4 "Hotcam" kit are GM part #12495494.... $37.00 from Jim Pace and are rated to .530 lift..
GM also used these springs in some of their ZZ series engines.. so they
are usable on 1st Gen SBC heads.
Closed pressure on the Hotcam springs is a cam friendly 101 lbs.
the Hotcam has .525 lift with 1.6 rockers...
For the 200cc runners to be effective they need to be filled with
air..... not partially filled... use the lift of the cam to help ensure this.
The old "Z28" springs for Double Humps have 110 lbs. closed.
Last edited by KyleDallas; 03-09-2007 at 11:38 AM.
03-09-2007, 12:39 PM
#15
Racer
Member Since: Jun 2006
Posts: 309
Likes: 0
Received 0 Likes
on
0 Posts
I certainly don't disagree with the reasoning behind the suggestions
of smaller runners if the heads haven't already been bought...
But I'd like to point out that the 1993 Vintage LT1/350 had 195cc ports from the factory... the LS1... at 346 cubic inches.. has 205cc ports from the factory....niether of these motors suffers lack of
torque. I'm not making the argument for larger ports.. but merely stating the combination counts... and that larger ports equaling poor
torque is not always the case.. a good guide, but no set in stone rule.
Cams are "head specific"... at least when your are serious about filling the cylinders. All "Double Hump" style heads flow very flat accross the .400, .500, .600 lift range... there's just not much flow to be gained
from more lift... this is not usually the case with modern aftermarket
heads, where you are often rewarded with 10,20 or 30 more CFM at each .100 lift increment.
Putting a Double Hump cam in a motor with heads that flow differently is defeating the purpose the better heads were purchased
for in the first place.
Chevy 492's flow
.400-198cfm(int)
.500-206cfm
.600-209cfm
.... very flat.. only 11 cfm difference from .400 to .600 lift.. not much
reward at all for the increased lift.... so why not keep the lift in the
mid .400 range for ease of wear and tear on the valvetrain???
World Products Sportsman II's 200cc flow
.400- 225in/150ex
.500-240/164
.600-243/162
Benefit of putting lift into the .500 area as opposed to the .400 lift
range is 15 cfm... a theoretic 30hp @ 2hp per 1cfm of flow. Horsepower thrown away by using a Double Hump cam. CFM increase at .600 is negligable... not really worth the extra lift.
If a ground up motor was being built... the GM Performance Parts
Bowtie Vortec Small Port heads would be a good choice... they offer
decent port size with good flow.... The Bowtie Vortecs.. as opposed
to the L31 stock Vortec heads are drilled to accept either a Vortec
manifold OR a standard 1st Generation SBC manifold.
GMPP Bowtie Vortec Small Port 185cc
.400-223 cfm
.500- 251 cfm
.600- 240 cfm
good healthy flow and smaller ports... a well designed head that
should be responsive... and that also flows the cfm's to make top end.
A good choice for a 327ci sized engine.
The springs used in the GMPP LT4 "Hotcam" kit are GM part #12495494.... $37.00 from Jim Pace and are rated to .530 lift..
GM also used these springs in some of their ZZ series engines.. so they
are usable on 1st Gen SBC heads.
Closed pressure on the Hotcam springs is a cam friendly 101 lbs.
the Hotcam has .525 lift with 1.6 rockers...
For the 200cc runners to be effective they need to be filled with
air..... not partially filled... use the lift of the cam to help ensure this.
The old "Z28" springs for Double Humps have 110 lbs. closed.
of smaller runners if the heads haven't already been bought...
But I'd like to point out that the 1993 Vintage LT1/350 had 195cc ports from the factory... the LS1... at 346 cubic inches.. has 205cc ports from the factory....niether of these motors suffers lack of
torque. I'm not making the argument for larger ports.. but merely stating the combination counts... and that larger ports equaling poor
torque is not always the case.. a good guide, but no set in stone rule.
Cams are "head specific"... at least when your are serious about filling the cylinders. All "Double Hump" style heads flow very flat accross the .400, .500, .600 lift range... there's just not much flow to be gained
from more lift... this is not usually the case with modern aftermarket
heads, where you are often rewarded with 10,20 or 30 more CFM at each .100 lift increment.
Putting a Double Hump cam in a motor with heads that flow differently is defeating the purpose the better heads were purchased
for in the first place.
Chevy 492's flow
.400-198cfm(int)
.500-206cfm
.600-209cfm
.... very flat.. only 11 cfm difference from .400 to .600 lift.. not much
reward at all for the increased lift.... so why not keep the lift in the
mid .400 range for ease of wear and tear on the valvetrain???
World Products Sportsman II's 200cc flow
.400- 225in/150ex
.500-240/164
.600-243/162
Benefit of putting lift into the .500 area as opposed to the .400 lift
range is 15 cfm... a theoretic 30hp @ 2hp per 1cfm of flow. Horsepower thrown away by using a Double Hump cam. CFM increase at .600 is negligable... not really worth the extra lift.
If a ground up motor was being built... the GM Performance Parts
Bowtie Vortec Small Port heads would be a good choice... they offer
decent port size with good flow.... The Bowtie Vortecs.. as opposed
to the L31 stock Vortec heads are drilled to accept either a Vortec
manifold OR a standard 1st Generation SBC manifold.
GMPP Bowtie Vortec Small Port 185cc
.400-223 cfm
.500- 251 cfm
.600- 240 cfm
good healthy flow and smaller ports... a well designed head that
should be responsive... and that also flows the cfm's to make top end.
A good choice for a 327ci sized engine.
The springs used in the GMPP LT4 "Hotcam" kit are GM part #12495494.... $37.00 from Jim Pace and are rated to .530 lift..
GM also used these springs in some of their ZZ series engines.. so they
are usable on 1st Gen SBC heads.
Closed pressure on the Hotcam springs is a cam friendly 101 lbs.
the Hotcam has .525 lift with 1.6 rockers...
For the 200cc runners to be effective they need to be filled with
air..... not partially filled... use the lift of the cam to help ensure this.
The old "Z28" springs for Double Humps have 110 lbs. closed.
03-09-2007, 01:07 PM
#16
Race Director
Port volume has a whole different characteristic on an FI motor that isn't trying to coax gasloline from a carburettor upstream aways.
The Bowtie heads I have are only 185 cc intake ports, and this is a large As I felt was OK on a carbed motor for normal street use, and the gas mileage at low RPM wasn't too stellar with a carb.
Doug
03-09-2007, 02:36 PM
#17
Burning Brakes
Thread Starter
Member Since: Jan 2005
Location: Leavenworth Washington
Posts: 768
Likes: 0
Received 0 Likes
on
0 Posts
If a ground up motor was being built... the GM Performance Parts
Bowtie Vortec Small Port heads would be a good choice... they offer
decent port size with good flow.... The Bowtie Vortecs.. as opposed
to the L31 stock Vortec heads are drilled to accept either a Vortec
manifold OR a standard 1st Generation SBC manifold.
GMPP Bowtie Vortec Small Port 185cc
.400-223 cfm
.500- 251 cfm
.600- 240 cfm
good healthy flow and smaller ports... a well designed head that
should be responsive... and that also flows the cfm's to make top end.
A good choice for a 327ci sized engine.
Bowtie Vortec Small Port heads would be a good choice... they offer
decent port size with good flow.... The Bowtie Vortecs.. as opposed
to the L31 stock Vortec heads are drilled to accept either a Vortec
manifold OR a standard 1st Generation SBC manifold.
GMPP Bowtie Vortec Small Port 185cc
.400-223 cfm
.500- 251 cfm
.600- 240 cfm
good healthy flow and smaller ports... a well designed head that
should be responsive... and that also flows the cfm's to make top end.
A good choice for a 327ci sized engine.
Really appreciate everyone's opinion here. You are all just making the odds of my having the engine I want a better probability.
Geek
03-10-2007, 01:18 AM
#18
And those are both direct port FI motors.
Port volume has a whole different characteristic on an FI motor that isn't trying to coax gasloline from a carburettor upstream aways.
The Bowtie heads I have are only 185 cc intake ports, and this is a large As I felt was OK on a carbed motor for normal street use, and the gas mileage at low RPM wasn't too stellar with a carb.
Doug
Port volume has a whole different characteristic on an FI motor that isn't trying to coax gasloline from a carburettor upstream aways.
The Bowtie heads I have are only 185 cc intake ports, and this is a large As I felt was OK on a carbed motor for normal street use, and the gas mileage at low RPM wasn't too stellar with a carb.
Doug
The LS1 also has 15 degree valve angle heads (not 23 degree)..which changes the flow characteristics and the standard usable port size...
The reason I'm taking a somewhat devils advocate position is...
What do you do when you're at the machine shop or the swap meet
and there sits a pair of 200cc Sportsman II's with 5 passes on them for
$300... your special, today only, cash price? and you have that
dusty 327 back at home you've been meaning to do something with..
Give up and say they are too big? or see what you can do with them??
215cc's we can probably agree.. with the reasoning we are using here
would be more port size than we would ideally want on a 355 ci SBC..
But when McLaren Performance tested the 185cc Vortec Bowties
vs. the 215cc Large Port Bowties on a stock ZZ4 bottom end... with the stock ZZ cam both the 185cc's and 215cc's made 348 hp...... when the cams were swapped to off the shelf units that didn't necesarilly favor making the 215's work... (cause they are going to need cam help in this type senario)..the 185's only bested the 215's by 9hp....
I won't argue that 200s or 215s are the better choice...but
can they be made to work with tuning and attention to detail??
I think so... would the $300 swap meet specials, even though they
have a larger than we'd like port size..still give substantially more
power than a set of Double Humps if say.. we bought some drop in
roller lifters for $325 and taylored the cam to the combo?? payed attention to all the little details..??
Here's an article on a 600hp 355ci SBC with 215's... below race RPM.
1. Unported Large Port Bowtie Vortecs.. 215cc
2. Unported Edelbrock Victor Jr. Mani
3. Mechanical Roler Cam
4. Tuning and keeping the power robbers at bay..
474hp.. 494 ft lbs @ 5000
527hp.. 503 fl lbs @ 5500
609hp.. 492 ft lbs @ 6500
http://www.chevyhiperformance.com/te...ine/index.html
Can anyone make the arguement that you couldn't make 400 plus
Hp at a useable, streetable RPM with good torque
on a 327 ci bored .030 over to 331 with strictly.
1. Torque plate bore
2. Premium rings on off the shelf forged or hyper pistons
3. Custom roller cam
4. 200cc Sportsman II's unported
5. Edelbrock mani and Demon carb
03-10-2007, 02:59 PM
#19
Melting Slicks
Nice Gift
Gtr1999,Gary that was a great gift you gave you son for graduation .So important to keep the younger generation involved.
Ps did not live to far from you i was from Shelton CT.
Ps did not live to far from you i was from Shelton CT.
03-10-2007, 04:35 PM
#20
I have to agree with some of the above and suggest that you go with a roller cam. If i could change one thing that i did during my frame off restoration it would be to use a roller cam and lifters instead of using the a hydraulic flat tappet replacement cam.
