305 heads question.

[Hotrodcort]

Anyone know the cc size for the 450 casting heads? I know the 601's are 58cc, but I can't seem to find info other that valve size on the 450's. thanks in advance!!

[carpoor]

Are they 305 heads? Everything I found online says they are 350 heads... center bolt valve cover pattern.

12506450

350

87-94

1.94/1.50

76cc

I think the cc is wrong, usually heads from that vintage are 64cc.

[carpoor]

Found another head casting that ends in 450...

376450 262,267,305 75-81 60 6 or 7 Exhaust Bolt Holes

[Hotrodcort]

Yeah, they're the 267-305 CID heads. Not sure witch one they came from. I know for sure that the 305 heads have higher compression to compensate for the smaller pistons. Bone stock 305's in early 80's K5 blazers came with 9:1 compression. Valves were small though. To my knowledge, 1.84 was the largest intake valve available. But any machine shop can remedy that. I have a set of 601's and the search shows 58cc, 1.84/1.50. Just can't seem to find cc size for the 450 heads.

[Hotrodcort]

Did some more digging and found that they are 60cc. Not worth anything really. But can make decent low end power on the cheap if you do all the work on them yourself. Ill use them for port/polish practice! Only paid $15 for the pair complete!

[carpoor]

Yup, that 2nd part # I posted, the 60 after the year meant 60cc. It was kind of vague without seeing the whole page I copied that from.

[Hotrodcort]

Cool, thanks for the info!