Technical Chevy Heads

I hope this is in the right place.

I'm not a Chevy guy but a friend is. He's building........well, you don't want to know what he's building....anyway, he's using a 283 from a 64 Pontiac and has a set of heads that he was told were from a 59 or 60 Corvette, (I think), early Corvette anyway, I've seen the double hump heads but these have just a larger single hump. Are they anything special or just sbc heads?

Thanks in advance.

 

Is the single hump a pyramid? If so they are power pack heads..... good heads for a 283..... small chambers about 9.5:1 with flat tops. Fuelies will flow better but lower the compression ratio....2.02 valves are a tight fit with the small bore and may not work with a high lift cam....if you want bigger valves stick with 1.94s

 

No, it's like a dome.

If I remember right, it looks like the second from the top of the left column.

 

The "Canadian Pontiacs" used Chevy frames and powertrains. The "Canadian" version of the U.S. power pack heads had a single "hump" instead of the triangle/pyramid. You heads are nothing special as far as being "rare". So, he has Canadian power pack heads. I am Butch/56sedandelivery.

 

Thanks Butch/56sedandelivery.

Yeah I know about the Canadian Pontiacs, these heads did not come off the engine he is using.

So power pack heads are better than average? Are they Corvette specific or is this another case of anything SBC came out of a Corvette?

Like I said, I'm not a Chevy guy.

 

power pack heads are better than average. they came on 4 barrel carb equipped v8 chevys. corvette or tri-five. they will flow better than run of the mill heads

 

Thanks wheeldog.

 

I've read that heads from mid 80s 3o5s that were used in the Monte Carlo SS work very well. The chamber size and valve sizes are very good for the 283 small bore. They flow pretty good and best of all, they have the hardened seats. I'm not sure, but I believe they were the 416 castings.

 

The Power Pac heads he has now are traditional and will flow just fine on a mild 283. Just make sure to use a good lead additive or have the machine shop update the valve guides for our ****py unleaded gas.

 

or seats

 

60s 2bbl and pp heads flow the same - the only difference is the combustion chamber size 60cc vs. 69 resulting in more compression....

 

Did they even make Corvettes in Canada? If not, then there's no way they could have originally came on one. Small valves and ports, and small chambers (usually, but some truck "powerpacks" went as high as 70cc chambers). I am Butch/56sedandelivery.

 

aha, this is what is so cool about the hamb- someone will have the answer.

 

Don't know if they made them here but we definately had them here, yes, I see what you are saying.