[Fastest65]

Hello agian
my short block is all done and drop off these heads that I have to get re-done
3964291 old LS6 454 rect port heads. Come to find out they has been port work in the chambers to the extent of 111cc up to 114cc where the factory says these heads should be 108.9cc's which is what I designed my cam pick, piston pick etc... Each cyl on each head is a little different. Got taken to the cleaners on these boat anchors. So much for honest joe's. Anyway I need a set of heads that will work with the already put together short block piston #141636, 14cc dome for these closed chamber 291 heads. I was looking at the Edelbrock #60499 with 100cc chambers semi-open. Will these work with the SRP-141636 piston? OR??? any thoughts. Didn't really want aluminum, but
these 60499 are. Shop is throwing the 291's back together with old stuff to cc all 8 chambers and if they are all the same or close on each head say 114 on one hea and 11 on the other could I just have them milled to 108???
Anhy help or thoughts would be great man
thanks

[cdminter59]

The Edelbrock 60499 heads would give you 10.8 compression. That is a little too high even for aluminum heads. You would probably have to use racing fuel. Edelbrock designed their heads simalar to the GM aluminum heads. Either head you use be sure and check piston to valve clearance. Using the GM head with 108cc would be about 10.2 compression which could use 93 octane. By the way i looked up the GM heads on several sites, they were selling anywhere from $650 on Ebay to $2200 on some Camaro forums. The less work that was done to them seemed to bring more money.

[Fastest65]

if the OE 291 heads are 108cc's and the pistons are exact
match SRP 141636 which is what I am making (LS6) I should
be ok with valve clearance. ???

[lmsport]

GM was just guessing when they published a head cc number. I have seen original BBC heads off by as much as 14cc. When the chambers are as cast, anything is possible. In the old days it was common to cc all 8 chambers and equalize as best you could. 2cc out of 110cc is not a show stopper for a street engine.

You will have to check piston to valve clearance yourself.

[Fastest65]

If you find after testing that you have cleance issues, "how does
a guy fix it"?