Well, I finally plopped down a fat sum for a ZZ502 long block (PN 12371204).

Since the top end will be unassembled, I'm going to take advantage of the opportunity and do a few upgrades. I'll be using an Edelbrock Performer RPM Airgap intake.

Any recommendations as far as Cam, rocker, spring, head work before I install the heads and the rest of the top end?

The intended use will be mostly street with occasional strip and possibly some open road race use (Silver State Classic).

Any recommendations on headers? I'm thinking 2" primaries, possibly 2.25", but don't want to run into interference issues with my clutch linkage and power steering box, and don't want to hang so low I can't get on and off my driveway.

Any recommendations on waterpumps, ignition and starters?

Thanks!
Tim

2 quick fixes for a 502s lack of power are:
Good single plane intake - Dart, Super Victor
Cam - around 250dur.
2" headers are good.

2 quick fixes for a 502s lack of power are:
Good single plane intake - Dart, Super Victor
Cam - around 250dur.
2" headers are good.

Wow 67RS502...Lack of power?:confused:
Did you have issues with your 502 being a dog out of the box?
Did you noticeably kill any low end torque with your single plane intake?

I've heard the 454 HO's are a bit sluggish down low, but I always felt that was due to those rectangle port heads. The 502's run oval ports which are much more responsive down low and lose a little up high to the rectangles.

These GMPP engines are actually about 10% under rated so the 502 is actually closer to 550 HP out of the box. That should push a 3200lb Camaro (3415 lbs with me in it) down the track in the mid 11's (barring poor traction or driver error). That's fast enough for me for now. The fastest ET's I've ever run were in th 12.90's with my old 69 Camaro, so I need to take smaller steps for now.

I see you're down in the low 10's with yours, so you're definitley accustomed to a lot more punch.

I'm going to leave the short block alone (might change the cam....but it's not at the top of the list as I want it to stay streetable and pump gas), but some head/valve train stuff I'm considering are adding a good set billet roller rockers and lifters in place of the GMPP stamped steel rollers and replacing the springs with Crane beehives. HOT ROD put some of these on a ZZ454 a few months back and it made a world of difference up high, controlling valve float and added some HP and TQ through the curve.

Also thinking about having the heads ported/polished a bit before installing them.

I might also go with a gear drive just because I like the sound...I'm not expecting a performance gain from it.

One thing that is not clear to me....Does the 502 need to run with a reverse flow water pump, or will the standard flow water pump work? I want to use my March serpentine system from my current 396 on my 502. It's pretty much brand new.

Tim

By lack of power I mean only 500hp, a decent SB will make that...
Kill low end tq, dont know never had a dual plane on it, but how much low end tq do you need? if youre towing at 2000rpm, then yes, you need as much tq as you can get. But if you want good power in the 4000-6000rpm range then a single plane is the way to go with a big motor and ovalport heads. You need to make power in the rpm band that your car spends going down the track which should be about 4-6K for a perf. engine.
550hp should get a 3400+lbs car into the high 10s@ 125+mph if its set up decent.
If youre doing a gear drive, do a cam swap too, you wont regret it... even a mild 240/245dur. cam will wake it up a bunch. The stock cam really sucks. Lunati makes softer lobes, and will rev better/higher. Head porting will cost way more then a cam, I'd do that 2st, but port work will pick up power a bunch too. Mill the heads and get the comp. up too.
Standard BBC water pump is right.
Dont forget the 2 most important things when doing a big motor.
Good fuel system - a 250GPH pump or better and 1/2" line.
Good exhaust system - 3" exhaust minimum, but 3 1/2" would be better.
X-pipe or H-pipe helps too.
If you dont take care of those 2 items, then it aint even gonna make the 500 adv. hp.
Believe me I've seen my share of 12 sec. 500 cube BBC, and thats just saaaad!

All good points. Thanks for the feedback!
I can't wait to get this bugger rolling!!!
This is the look I'll have on my face.
:D

Forgot to mention...
I do plan on adding a Procharger sometime in the future (after I minitub the car and get the 6-speed in there), so I'll leave the compression as is. I only plan on running 6lbs of boost max, so the 9.75:1 compression should work fine with that.
Any thoughts?

I own a GMPP 454HO, ZZ502. I agree with both members. 67RS502 is right when he states the 502 has "lack of power" by that I believe he means the 502 leaves a lot of HP on the table due to their small pencil like bumpstick and intake.

Meanchicken is also correct by stating he wants the pavement wrinkling torque down low of the 502 the way it is. I faced this dilemma and took the ZZ502 and put in a new cam by comp cams...l forget the grind, but call them and they will instantly know which one it is. Then added 1.7 roller rockers. I also switched from the oem intake to the Air-gap since it made more HP on these engines according to the article from Hot Rod.

The article was right! Made a large difference in performance without sacrificing driveability. According to the article, the single plane only made about 4hp more than the air-gap but the torque curve was fatter with edelbrock.

Thanks, 4MuscleMachines!
Did you also change the valve springs?
Have you pulled any E.T.'s yet?


Hey, 67RS502.
What headers are you running?

Anyone have anthing to say about slapping a Procharger on a ZZ502 wit the stock short plock assy?

Hey, 67RS502.
What headers are you running? Any fitment issues?

Hey, 4MuscleMachines.
Have you ET'd your car with that 502 in it yet?
What were your times?
What headers are you running?
Did you install the beehive springs along with your cam and rocker swap?

Anyone have any feedback regarding dropping a Procharger on a ZZ502 without changing anything in the short block rotating assy?

Tim

Swapmeet Hooker super comp 2" headers, that have been cut at the collectors, and flowmaster tri-y collectors installed