Thread: Head CC Question

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I need some verification here. Mortec and 2 other sites I refer to list the SB462 heads at 64, and 65 cc's respectively. My machinist, who I trust, says they are 68. Machine shop says chevy made 76, 68's ( in this case) 64's in the way of the 461 heads and a smaller rare 58 head. I need to pick pistons for my block and I need to know. Does anyone have the definitive on these heads so I dont have to cc them. Is 68 a good number? Obviously if I wrong and pick the wrong pistons......so........, a little help here? I think they are 64's myself.

Originally Posted by jimmyjeep

I need some verification here. Mortec and 2 other sites I refer to list the SB462 heads at 64, and 65 cc's respectively. My machinist, who I trust, says they are 68. Machine shop says chevy made 76, 68's ( in this case) 64's in the way of the 461 heads and a smaller rare 58 head. I need to pick pistons for my block and I need to know. Does anyone have the definitive on these heads so I dont have to cc them. Is 68 a good number? Obviously if I wrong and pick the wrong pistons......so........, a little help here? I think they are 64's myself.

If in doubt take the old chemist buret to them and find out.

Oh Eric, I knew you were gonna say that. I told my wife I was gonna have to set a burette up. I just wondered what the REAL published cc number is suppose to be on those heads. It's kinda strange that those heads have been around for 40 years and noone has a standard number to publish. They range from 62-68, that I've found with the majority agreeing on 64.

Originally Posted by jimmyjeep

Oh Eric, I knew you were gonna say that. I told my wife I was gonna have to set a burette up. I just wondered what the REAL published cc number is suppose to be on those heads. It's kinda strange that those heads have been around for 40 years and noone has a standard number to publish. They range from 62-68, that I've found with the majority agreeing on 64.

You see I never really trust what I read.
I would really have them checked.
You will sleep better at night knowing you did it the "right way".

I hate it when your right. . I'll cc them this weekend and report back. They are at the machine shop right now, getting a beauty treatment. (My wife understands that terminology)

With the producation capabilities, or rather the lack of them, back when these heads were produced someplace between 62 and 68 is probably correct... The guy who said they were 62 might have had a set that had been milled once upon a time and the guy who sez 68 might have got a little carried away cleaning the combustion chamber on his heads...

Yupir! AND.... that brings up a real interesting point. If something alot of us have taken for gospel for years, could be that far off, such as the published cc volumes on a bread and butter chevy, learning to do (or doing if ya already know) a cc job is a really important step for beginners to know and understand. Alot of folk try to squeeze horsepressure out by shovin' stuff in, but I think its the lost art of building steps that give ya a tire twister.

Yep, the advice I give in a compression ratio post on another forum is for the first timer to purchase a cc kit from Summit and do his heads so that he absolutely knows what they are. I further advise to spread the word in the rodding community that you will cc a set of heads for $35. Three sets of heads and the kit is paid for.