this question isnt directly related to camaros, but ive got a 1973 454, and heads off a different year, i believe 1976. the block and heads are different colors, but when i put the heads on the block it seems to fit. any body have any experience with this? i just need to know about the compatibility, would there be problems with compression or anything?

There is a casting number on the heads you will need to know so you can determine what you have. Take a look at pistons, flat tops, domed, valve reliefs? Know before you just assemble parts. They will bolt on but are they what you need, find out first. Lots of info on this sit to help you out.

He, He!! I feel an "epistle" coming on...

Fwiw, there are several Mark IV to Gen. VI BB heads out there. (I mention this b/c the Vortec 8100 BB motor is a completely different animal and won't be discussed here!)

Early, closed chambered large oval, (intake port is oval and taller then it is wide - 235 to 262 cc sizes).

Early rect. ports, (intake port is just great big round-cornered rect! - 290 to 325 cc's).

Later, open chambered large oval and rect. ports.

Peanut port, (intake ports are wider then they are tall - 198 to 230(?) cc's), truck/2-barrel open chambered heads.

Smogger, open chambered large oval heads that have the quench flat removed and squared up the same as the intake valve.

Generally worked over large valved, closed chambered large ovals with flat-top OR low domed pistons along with steel shim headgaskets and a quench distance of from .035" to .045" that combine to create up to a 10 to 1 CR. make for a VERY powerful BB pump gas burning combination.

BUT the deal here is to match combustion chamber size to piston head type so that you arrive at the about 10 to 1 CR., SO THAT you can still run good PUMP GAS, b/c open chambered heads DO tend to breathe easier then the closed chambered heads but are more detonation prone then the closed chambered heads.

Again, fwiw, GM created the open chambered heads for smog reasons and then carried the design farther when they made the true almost completely quench-less smogger heads I mentioned above!

It was deamed that closed chambered heads are dirtier combustion-wise then open chambered heads b/c there is more metal surrounding the combustion process which tends to cool the flame and thus creates more overall combustion by-products that are better known as "smog precursers"..

Boy, did I get carried away!!

pdq67

PS., worked over, big valve peanut port heads are OK on the smaller 396/408 motors up to about 55 to 5700 rpm then they run out of suck due to the small ports. AND they are down-right powerful on a 454 Duelie Truck motor tho that is used for pulling a load b/c they create tremendous torque at the lower rpms.

The large ovals can produce great power up to a medium power 540 motor! And up to about 6500 rpm on the 454/510 motors! And some have mentioned in passing that they may, just may be slightly too big for the 396/408 sized motors compared to the 454/468/481/496 motors.

Rect's are GREAT for large-to-huge, high rpm BB's and are generally thought to be too big for MOST street motors even tho some guys run them and like them.....