I don't have a Chevelle but I have been reading on this site for over a year now. I am a member of the Nastyz28 BB. You guys seem to really know what you are doing as far as engines go and I would like some help sorting out my 406. DCR and such has been driving me crazy for 2 nights now and I cant seem to pick a cam or heads. Here is what I have so far:
406 2 bolt undecked
5.56 rods
7 cc KB hypers
487 heads with big valves and 75 cc according to mortec
3 angle valve job
.039 head gasket, near as I can tell...its a fel-pro part coming in the speed pro 400 rebuild kit
3.42 gears
2500 stall
THe problem is, the engine is assembled without the cam. Therefore, I do not wish to change the pistons. I am looking for a solid cam to be different and I would like to find a way to get some Vortecs on this sucker. When I run Pat Kelly's DCR calc, I cannot seem to satisfy the safe quench paramaters and get a DCR of under 9. Can you guys help me?

MaTt

There are no thin heads gasket that I know of for the 400 engine. What is the deck height? If it is ~.025, there is no way I know of the get proper quench without decking. With a .025" deck and .039" gasket, I get 9.64 for the SCR. A 258º cam on 110º LSA installed at 106º is the smallest I'd use (8.3 DCR). A 280º cam is about the biggest you'd want (7.7 DCR). Don't forget to use advertised duration, not .050".

page 134 of the April Chevy Hi Performance (top lefthand paragraph) says that though discontinued in late 2002, there is a factory shim gasket (.026) that can still be found at some dealerships. P/N 3997790. Will that make a difference.

MaTt