72Tornado

Okay, this summer I plan on rebuilding my 72 L-48 with a basic 383 stroker kit - nothing too crazy, just one of those $1,000 cast kits. I'm looking to get 425 or so crank hp once the engine is in the car and still be just fine to drive daily through an M-20 and 3.08 rear. My budget for the entire top end (including lifters, pushrods, gaskets, etc.) is $2,000 at the most. I'm most likely going to with a Performer RPM manifold since I've heard so many good things about it. What are some good choices for heads/cam? I know some manufacturers out there make top end kits...I was looking at Trick Flow's 465hp kit, but I was worried the cam might be too big. It specs out at 230/234 @ 0.050 and .528/.539 - am I right in being worried, or would this be fine through the 3.08 for a daily driver? I definitely want a little lope to the cam, but I want the car to have good street manners too.

Opinions?

*edit* Couple more questions - firstly, how much would it cost for a shop to tear down and rebuild the engine with the stroker kit? I will be doing the actual engine swap myself, but will be getting the assembly done by a shop (I could do the top end if absolutely necessary). Will I need to swap out the stock L-48 fuel pump for something that flows more? Also, will a Holley 670 Street Avenger be alright for this motor or is it too small?

big_G

The Trick-Flow kit sounds fine. I don't think the cam is too big. Maybe marginal if your's is an auto. trans. Nothing a loose torque converter can't fix!...

comp

M-20

big_G

Ahhh...excuse me! I have CSS syndrone (can't see shyte). That combo begs for a Richmind 5-speed trans.

Emeightch

What about a Edelbrock RPM Performer Package? That way all the parts will talk to one another. The last time I looked, they were about 1600 out of Summit. I do think 2k may be a little low for this project. A good stroker kit will be about $600-800 (I'd go Scat), Machine work maybe $500 plus the $1500 top-end and misc assembly.

72Tornado

I looked at that one too...I know the Trick Flow kit will outperform it, but it'll come down to my budget (and if the TF kit would have good road manners).

The $2000 budget is JUST for the top end. I'm setting aside $1,000 for the bottom end and then $500+ for assembly and labor...I have a bit over $3500 to spend in all.

How much is it going to cost to have a shop build the engine? I will be doing the swap myself, but I plan on dropping the motor off to have it torn down and rebuilt with the 383 kit. If my budget got too squeezed could put together the top end (would be my first time doing so)...

ajrothm

For $3500 you can buy a 383 crate thats already built, dyno tuned and 1yr, 12k warranty from TandL. 400hp.

If you do your own motor, the stroker kit is $700-800 plus machining the block. Thats where you will spend some $$. Boil/.030 bore/hone/cam bearings/freeze plugs, stroker clearancing and line boring(a must if you are installing a different crank) will easily run you $500-600. Thats going to leave you at $1500 for the bottom end, the $2k you speak of for the top end burns up your $3500.
Hell you could get a new GM block for $600 and clearance it yourself.

Personally, I would buy one already done by someone who builds engines everyday, and its actually dyno tuned, not a clone of another motor that "SHOULD" make this much power. Pull your original motor and store it for the #s. Call Lloyd at T and L, he will work with you.


Get the engine, stick it in and go. 400hp at the crank is easily 300+rwhp. That will get you high 12s

72Tornado

I thought crate motors were rated w/o any accessories or full exhaust...am I wrong? I would be happy with 400 crank hp once the engine's in the car, but 400 'gross' engine hp just wouldn't do it. How can I get into contact with T and L and where are they based?

ajrothm

Ya crate motors are rated with headers, no accessories other then water pump, and sometimes they use electric water pumps for dyno purposes. I have never used anything from www.TandLengines.com but they have all of the hardware, procedures and pricing on their site. I called and talked to Lloyd about a 383/408 and a 496. They have good prices, dyno tune with your carbuerator and distributor. Its turn key with a 1yr, 12k warranty backed by T and L. Just check out their site and call em. I am probably going to use them. Everyone else marks stuff up WAY too high.

THe thing about other crate companies is that they don't dyno YOUR engine. They build your engine using a combo that HAS MADE that certain HP number they are quoting you.

If you dyno YOUR engine, its broke in, valves adjusted and checked for leaks before you put it in the car. Plus you know how much power you REALLY have. Take your crank HP, subtract 25% for an auto/stall and thats pretty close in guession your rear wheel HP. 300rwhp is enough for 12.90s-13.20s depending on the setup/tires/driver. My TA went 12.90@108 with 310rwhp at 3700lbs raceweight. 3.42s and a 3500 dump on ET streets. 1.88 60'

72Tornado

I'll check them out. I know 300RWHP would be enough for high 12's on some stickies...but consdering the current crop of performance cars, I wouldn't exactly mind putting out something more like 340RWHP. I also don't see a 400hp crate motor giving me 300RWHP. I'll give some of the shops around here a call and do some price comparisons...

Thanks for the link!

79MakoL82

Personally, I think you might be a little disappointed in the bottom end of your HP/Torque curve. Look at what RPM you make 465 HP and ask yourself, "How much time am I going to be spending there"? You might be happier with a lower peak HP but more HP/torque in the lower rpm's than having that high HP number at 6,500 rpm's where you will rarely run your engine. That's more of a bragging rights thing. Take a look at the 420HP package. It has a flatter torque curve and makes peak power earlier in an area your engine might actually see from time to time. I wouldn't push a 34 year old rebuilt L-48 to 6,500 RPM's on a regular basis. But that's just my opinion.

JustinD

I tihnk you will be mid to high 3k also. I have about 2500 into redoing my 350, and I left the low end alone mostly.

72Tornado

Wish I had some dyno charts or anything to actually see what the power curves look like You're right, I'm not going to be spinning to 6500 very often...but I have no idea how the low end of those two packages compares. I'll give TF a call and see if they can provide me with some more info...

MYBAD79

For $800 you get a new GM 4-bolt block with a 1-piece rear seal and prepped for hydraulic roller lifters/camshaft. That's probably $200 more than you will spend to get your old block machined. Just my 2c....

ajrothm

Ya especially with 3.08s in a heavy car with a 2.20 1st gear.

If your motor makes a TRUE 400hp on an engine dyno with the water pump/fuel pump and headers installed= 400 x .75 = 300hp. The key is making the true power on an engine dyno and with all dynos, there is always a number of variables that distort the HP readings, not to mention a general difference in dynos and conditions.

I seriously doubt that if you buy that Trickflow kit and slap it on a 383 shortblock its gonna make 465hp... Remember, they have to advertise to sell those kits. I have countless buddies that have bought the Edelbrock RPM top end, slapped it on a 350 and made 260-275rwhp with a manual tranny. Damn ZZ4 will do that with ****ty L98 heads. Don't believe everything you read.

72Tornado

I personally don't see how I'd only have a 25% loss from gross engine hp to RWHP after all accessories and full exhaust, even through a manual. I would expect more like 30-35%.

Certainly I'm wary about any and all advertising. I know another member here bought the 350hp kit and found out that the rating was pretty accurate...and I know another member here has the 465hp kit but the engine isn't in the car yet. I may well end up going with the 420hp kit anyway, depending on what I find out about the power curves. The latest issue of CHP had a comparo of a bunch of different heads under $1000 - the Trick Flow ones ended up giving some very good numbers on a pretty standard 383 (don't remember the exact figures). A cam is a cam, so there's nothing to doubt there, and I know the intake I'm going with is good. Considering the 350hp kit dyno'd 280RWHP...I would definitely expect over 325RWHP, perhaps as high as 340, with the 420hp kit...

I wasn't about to go with the Edelbrock kit anyway, I can't see how the heads would be big enough for a 383.

Thanks for all the help.

gyopp

ajrothm is steering you right with T&L. I am sure there are others out there that are just as good but they wont be much cheaper if any and I would want some feedback from others that bought from them. T&L just built me a 408. I went to Charlotte and watched the dyno run myself. They will deliver what they promise. When I got my motor home I put gas and oil in it and started it. It is tuned and ready to go, no further timing or carb tuning required. I had them build my motor for big torque #s because I will run this mostly on the street. They will build you what you want, just call loyd and tell him what you intend to do with it.

LFZ

I'm running an awesome 383, with a M20, and 3.08 rear...very streetable, and very fast....might wanna save up, and extend your budget if you want an honest 450+hp. JMO.

72Tornado

Specs? How much did it cost you all in all? Dyno numbers?

BTW, I've always loved your car...those wheels are just gorgeous :drool:

450+ crank hp is probably more than I need/can afford right now, to be honest. That'd put me at nearly 400RWHP...and I'd be happy with 340-350 Being a college student and only working full time over the summer and winter break doesn't give me too much cash to throw around, heh.

79MakoL82

The Summitt Racing catalog has a chart for each trick flow package. If you have one of those laying around, take a look.

I think the TF packages are a great value. I was looking at them to eventually do a top end buiild up on my L82. I have TFS heads on my Z28's 383, and they're good heads for the price. The 465hp package is tempting, but when I really thought about it, I was leaning towards the lower peak power package. As I recall, the HP curve between 3,500 to 5,500 was similar to the 465 package except a little more HP down low and a nice flatter torque curve for the lower package. The draw back of the 465 was a more curved torque curve going lower at lower rpm's, and the 465hp was made way up around 6,500.

I'll take a look at my catalog tonight and see if I can't give you more details and comparisons.