CFL34

I WANT TO PUT A BB IN MY 72' IT IS PRESENTLY A 350 I'M WONDERING IF IT WOULD BE EASIER TO BUILD MYSELF OR BY A GMPP 502 PROBLEMS KEEP COMING UP WITH THE 502 -CLEARANCE-HAVING TO RUN A ELECTRIC FUEL PUMP- THE MOTOR NOT BEING CAMMED ENOUGH ETC,ETC, ANY IMPUT WOULD BE APPRECIATED. WHENEVER YOU THINK OF 68' TO 72' VETTES YOU JUST THINK BIG BLOCKS SO I GOTTA DO IT ONE WAY OR ANOTHER!!! :mad :mad :mad :mad

stickboy

I would think it would depend on how you feel. I can't say I've heard anything overly bad about the GMPP 502's, but if it's not what you really want then build it right the first time.

Also, please turn off your caps lock. It's hard to read and some consider it to be the same as yelling

1Bad69

build a 540.... :thumbs:

AGVI

...then give it to 1BAD69!!!

:thumbs: then he'll give me his engine....and I'll give you my L48...OH! you want power, not a lawn mower!!!

Seriously, you should consider building it. :cheers:

norvalwilhelm

Alot would depend on your person skills. Are you competent to put a motor together or is it a learning process?? Do you have the parts to build your own bigblock? Those 502's are nice motors. As for electric fuel pumps I wouldn't have it any other way. I also like hydraulic clutches so for me that is also not a problem.
I would go the 502 route.

72 Stingray

If you really want a BB GM crate motor and a mechanical fuel pump, a ZZ454 re-cammed with a solid street-roller should do 11s in a 72 C3 without much trouble (if you can hook it up and don't break anything).

If you want to build from scratch with new good-quality aftermarket parts, a 509 or 540 can be had for about the same price as the above if you go with a flat-tappet cam.

This opinion was formed by running numbers for way too many hours trying to make the same decision you are. Still haven't decided either... :crazy:

DJ Dep

You can get crate motors in varying states of build from various places. Short block, long block, or complete motors. Check this place:
http://www.shafiroff.com/

You can go a lot bigger than 502 and a lot hotter too. All depends on what you plan on doing with it and your skill level.

Dep

Glensgages

I witnessed a guy with a ZZ502 in a '75 Vette run 12.03/112 last year.
I helped him load it onto his trailer after busting the rear-end on the 2nd run;
it idled at 700 RPM, had no 'whiff' of race gas, and he claimed is was 'box-stock'.
The car had headers, a THM400 with an 'on-sale' 10" converter, 3.90:1 gears, and 29" x 11" M&H RaceMasters.
By-comparison, bence13_33 ran 12-teens/117 with his 'built' 468" w/ a stick & 4.11s.
I attribute the quicker ET to the ZZ502's 567 ft/lb of TQ, as bence13_33 obviously makes more than 502 HP, but the '75 ran quicker w/ 5 less MPH trap-speed.
I have heard that the ZZ502, in stock confoguration, had a lifter-problem (collapsing?) after repeated high RPM running, which may've been corrected since I was told that info.

GDaina

comparing parts between a 454 and 502 (502-540), assuming you're buying all new parts, and assuming you're assembling the motor, the price difference between a 454 and 540 is chump change. Price of cranks, regardless of the stroke are identical, same with rods, regardless of length, pistons and rings, again should be close that price would not be a factor, same with the cam. The block, however might be a different story, new vs. used. If you decide to go with a used 454, you have to factor in the cost of .030 bore and possibly line hone...those costs may bring you to the price of a new block.

I would not buy a crate 502, you are stuck with the cam and compression ratio that the General decided to put in the 502. Also, the 7/16" rods that's used in the 502, are heavy, heavy, heavy...you can get lighter 3/8" H beams that are rated for higher H.P. You can use the cam of your choice, same with pistons, use internal balanced crank rather than external....you have more options by building your own, and to wrap this up, the cost is almost identical to build a 454 or a 533/540 cube motor.

72 Stingray

And very likely the broken rear end too! :smash:

427Hotrod

As mentioned...depends on your skill level and ambition.....

But you really can build a much stronger motor for the same $$.

If you do some price searching, you can find great deals...you just have to keep your eyes open.

I spent around 7K on my 540 for the first version that made 732 hp on pump gas. That included every single piece new except intake, oil pan and a stud girdle. New Merlin block, machine work,new Brodix heads, new crank, rods, pistons, roller cam/lifters, rockers, pushrods, fabricated valve covers, balancer, timing cover, chain etc etc, ARP bolts, gaskets and on and on. But I did all the assembly, mock up etc.

New cam, intake and head porting put it at 825 hp still on pump gas.

Some prices have actually come down on this stuff lately. I saw some dyno time only AFR CNC heads for sale the other day from the guy at AFR that designed them for about $800-900 less than list. You just have to keep your eyes open.

But as mentioned there is always the Shafiroffs, Bill Mitchells, Reher Morrison's or even your local engine shops that can build you one. If you know a good local guy with a good rep, sometimes it's worthwhile to do business with him. You save shipping costs and you have someone to turn to easily if there are problems whether it's mechanical or tuning.

If 500 HP is all you want, then it's a toss up...but if you want to go out to 600-700+ then go for the other stuff, it's a better way.


JIM

verskel

Yeah, go for the 540 c.i.d. :thumbs:

Just make sure you dress it up like a 454 and don't tell anyone. :jester
...Yeah, it's just the stock 454 :rofl:

markdtn

:iagree: It all depends on if you have space, knowledge, or some good friends that do.

JohnS_77

Won't the 502 come with a warranty?
If I was faced with this decision, I would buy the 502. Not just because of the warranty, but because I lack the skills required to build an engine. :nonod:

Larry3x2

I would go to a competent engine builder. I noticed you didn't explain what you intend to do with it. This is a must answer for any builder before they start. My info is that the 502's are built on a production line in Mexico and they occaisionally have problems. One didn't make the HP, another had wrong pushrods. Ask if the GM warranty guarantees performance. If you buy from a builder you can attend the dyno run and have it cammed etc for you specific need and write your final check while it's still warm.

Larry