Head chamber size..??

**WILMASBOYL78** · #1 01-23-2005, 05:24 PM

I have a pair of chevy BB oval port open chamber heads. Casting # 6272292 dated A1872. According to Mortec charts these are for 71-72 402 and 454 motors. They list heads CC's for most of the heads in their file but not this one. Colvins book shows a similar head with a 113cc chamber. Thinking about using them for one of my projects with the obvious upgrades. The engine they came off was a CTB code 1972 402. Just wanted to know the chamber size for these heads before I start. Any help would be appreciated. Tom

Chevy454 · #2 01-23-2005, 05:44 PM

Not sure exactly what you have in mind, but I'd cc those heads to see where they're at NOW...the chambers are cast BIG from the factory, and if they've been milled quite a bit then they're going to be too small. Example: the chambers on our 840s were advertised at 107cc or whatever, but when I cc'ed them they were in the 112-113cc range...combine those big chambers, a good .038" Fel Pro gasket, and the stock 11:1 pistons, and you'll be right at 10:1 and can run an L72/L78 on pump gas! You can buy a cc kit from Summit or Jegs cheap...would be cheap insurance.

**WILMASBOYL78** · #3 01-23-2005, 06:31 PM

That is exactly what I have in mind. I want to replace the rect port heads on my 454HO with a set of oval port units. Obviously I am planning on 219/188 valves, hardened seats, good hardware and porting work. Everyone tells me that a set of well prepared oval ports will produce more torque and low end street power for me. What is your opinion on the Gm performance aluminum heads, advertised as 110cc.???

Thanks, Tom

Chevy454 · #4 01-23-2005, 06:40 PM

No experience with those particular heads, but I've talked to a few folks who've bought GMPP aluminum heads and they liked them...hard to beat the price.

**WILMASBOYL78** · #5 01-23-2005, 06:48 PM

Who is the cylinder head guru on this site???

tw

**kwhizz** · #6 01-23-2005, 11:17 PM

Just for what it's worth.......I'm putting together a L-89 engine and have a set of untouched 842 Aluminum heads that the book said should have 107cc chambers........when we cc'd the heads the chambers were 111 cc's across the board.......
Can't wait to get some miles on this one.....

Ken

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