I have a 406, deck untouched, Manley forged flattops(valve relief cc not sure of) and stock 5.56" rods. I've been using Pat Kellys DCR calculator and coming up with what I think might be some high quench numbers. The heads I'm using are AFR 195's(thx Wolfplace!) w/74cc chambers. With a 0.039(4.166 bore) head gasket I get 0.074 quench. Everywhere I've read that 0.035 to 0.055 is best depending on use.

Am I actually ok with so much quench or should I be looking at using a thinner gasket? The car is street driven and used in autox and road racing events(3200lbs, 91 camaro). Compression with the 0.039 head gasket and XE274 comes out to just under 9.9:1 static and 8:1 dynamic.

What do you guys think?

I am having the same problem.

MaTt

Fel-pro's 1094, .015" rubber coated shim headgasket will need tweeking to work on your motor, but it isn't much of a job to tweek them.

It will get you down to .059" if your DCR doesn't go too high for pump gas.

I ran the .022" steel shims on my 406 by drilling the steam holes by using an old 400 headgasket as a template.

Then I mocked up my motor and reached up inside it with no pan or rotating ass'y and scribed where they hung over into the chambers by each intake valve, (I ran stock, big valve, -461's), and then I gently ground and filed them as needed to clear.

Then put them on with several coats of Copper-Cote and I "anally" torqued them about three times!!! Over a couple of days after driving to work.. That heat cycled them AND it workd fine for me!!

pdq67