Recipe Help

[gtobob67]

A friend of mine just purchased a 60 corvette that has an early 70s 350 in it. I'm helping him switch out an intake (Cast iron) and carb. He's got a 69 350 truck quadrajet 7029223 and I want to set it up right for him. Engine is a fresh .60 over 350 with 76cc heads (882s) which I believe will put him in the 8.5-9.1 compression ratio range. The cam is 224-224 @ .050  .450 lift on a 114 LSA. The vette is a 4 spd. I'm leaning towards Cliff's second recipe because of the cam and could use your assistance in the decision. Thanks in advance. Current carb set up as follows

Idle tubes   .036
Idle down channel  .055
Lower idle air bleed .060
Upper idle air bleed in main body  .078
Main body air bleed  .046
Main air bleed air horn  .046
Main jets  67
Primary metering rods  .038
Secondary hanger  J
Secondary metering rods  AN
Idle bypass air   .066

[Cliff Ruggles]

Calibration looks good for that combination provided the engine has flat top pistons, tight quench and a thin head gasket.

Very poor cam choice for those heads.  882's have very restrictive exhaust ports, so a dual pattern camshaft would be part of the engine build for sure.

We actually consider those heads "door stops" here.  Compression ratio would depend on type of piston used, dished or flat top, how far it is below the deck at TDC and head gasket thickness.

With that much camshaft you'd need to be near 10 to 1 compression for sure, it's going to be a "turd" at or less than 9 to 1....IMHO.....Cliff

[gtobob67]

Thanks for the reply Cliff. The engine does have flat top pistons but the head gasket thickness is an unknown. I'm a Pontiac guy just helping a friend out. Don't know much about Chevys but I  do know those heads and cam are a very poor choice. The owner spent a lot of money purchasing this car and his expendable  cash flow is gone. I'm just trying my best to get this on the road for him. It's amazing how some people when doing a build take all kinds of short cuts, and this car is a perfect example. Everywhere I look I find issues. Electrical, mechanical, cosmetic, all there. Good thing the price was right. When all done at least the Quadrajet will be right.Thanks!!

[Cliff Ruggles]

I learned about the 882 castings back in the early 1970's when they first came out.

You could build a 350 SBC with a Crane Blazer 288H cam, flat tops, and 441, 336, 487 or 993 "smog" heads and it would tear your head off and throw it out the window in a 4 x 4 truck application.  For our lighter street cars with a little gearing/converter we used the L-79 or Crane Blazer 300H cam, same result.

Build the EXACT same engine with 882 heads and I can't say TURD loud enough here.  Those engines with the only difference being the heads made the vehicle act like it was pulling around a 1500lb sled all the time, those engines revved slower, and SERIOUSLY lacking in upper mid-range and top end power.

The Crane 288H and 300H cams we used were single pattern, which worked flawless with the better heads, and very poorly with the 882's.

I'm a quick learner with these things, and only used the 882's ONCE, but over the years, and even today (with all this good info out there) I still see folks using them, instead of the much better aftermarket offerings, or more desirable early iron heads.  The only good sound 882 heads make around here, is when they 'tink" off the dumpster outside the shop!!!.....Cliff