69 Chevy

Moderators...does this pass muster for reviving 2+ year old threads???

Bullshark

l88rocket

I like the 502's, but i don't like them "stock" anytime i use one i change the cam in it.

MikieTallapoosa

.....had to make my own 'elbow' for the front but looks like yours....I must be on the right track.... Where did you get the 502 numbers for the hood please and is that a 'one piece' hood or did you have to modify an L-88 like I did ?......Looks great by the way-nice paint.....

Kerrmudgeon

Whatever one you decide on, you may want to rip it down and check it for clearances. Most of them are way off, and don't come close to the advertised horse power. At the machine shop I use last year, they had to redo a GM performance 502 that was a complete DOG. Just sayin......

c502cid

My first 502 was a 502 HO short block that I put cast iron oval port Merlin heads on, changed the cam and ran a 4bbl Holly Projection TBI on it. Had it in a GMC crew cab dually, 4x4, that weighed 7200 lbs and the truck could flat out scream from a dead stop. Loved doing the So Cal freeway on ramp drags with it, always smoked the little Honda's..
I still have the motor, apart in my garage waiting for something special...

I have a Ram Jet 502 sitting in my 71 Blazer, still being built... haven't fired it up yet.

I originally was going to put a 502 in my 68 427 4 spd Coupe, but truthfully, I loved that 427 motor too much to pull it. Wish I still had that car.

Hard to go wrong with any big block really....

DAVID SLUDER

Im planning on a ZZ502 install in my 69 in the next year, what cam would you recommend to wake up the 502?

63mako

Don't know why anybody would go with the GM 502 or a 496 built from a used stock block when this is available at the priuce it is at. Check the parts list.
http://www.ultrastreet.net/engines/540_realstreet.asp

DRIVESHAFT

Being able to buy a 496 from Mark Jones for $3000 less that makes more power is going to appeal to a lot of people.

Bullshark

Thanks Mikie, The 502 numbers come from TrimParts. They are a little pricey, but in keeping with tradition, the BB hood needs a badge I took an old Eckler L-88 hood I had and raised the center ~ 1.5"

While the ZZ502 can certainly benefit by a higher lift cam, it is not the first thing I would/did do. My RJ can shred the tires with the stock cam as it is so, adding even more hp seems down the list a bit.

First on my list would be Fuel Injection. If I had it to do over, I would opt for a multi-port /throttle body setup similar to the Holley intake on my 69. If for no other reason than to not have to deal with the hood clearance issues. Get one of the latest Holley EFI ECU's like the Avenger or HP systems. Dominator is tops but probably overkill.

My 69 with stock L-88 hood and old Commander 950 ECU


Secound would be to put in a decent overdrive transmission. I opted for the Tremec 500 with 308 rear differential. the first gear setup is healthy approximating the old Muncie 4-speed with a 4.11 differential first gear. the overdrive 5 gear runs about 70mph at 1900-2000 rpm. Top speed is crazy scary.

If you do go with the RamJet, pitch the MEFI ECU in the trash and go with one of the Holley options above. I put a slightly larger throttle body on the RJ intake (2" throttle ports). The old stock TB is small for that engine. That takes me up to ~6K rpm before it starts to fall off with the stock cam. If you are still feeling HP deprived, a cam would be next, but damn, you better have the rear end and tires to stand up to it. Right now, frying the tires acts as a fuse for my drive train holding together.

I use the RJ as my driver, not daily but I'm not at all afraid to take it on longer trips. My butt suffers though..

The carb may seem to be an easier way forward, but I'm telling you, Once you go EFI you will not look back.

Just providing my experience and 2 cents here. Take it for what it for what its worth.

63mako

I suppose your right on the Mark Jones engine but it is a used stock block and heads. Apples and oranges. As far as the GM 502 goes no comparison for the money.

bashcraft

Obviously it does.

Ben Lurkin

Using the factory 502 lifters, etc. this is about as much as you can use:

http://www.summitracing.com/parts/CRN-168741/

.610/.625 lift

236*/244* duration

I've had a couple of zz502 cams reground to this spec by Delta cams in Tacoma, WA for $100. This cam really wakes up a ZZ502. It has a nice split on the exhaust duration to help out the exhaust ports.

Any more lift or duration than this and you need to upgrade lifters, use heavier pushrods, different valve springs, etc. Be sure and check the slot/stud clearance of your rocker arms The rockers usually need a little extra clearance ground into the slot so they don't hit at full lift.