I was one of the so called lucky ones who actually received their 408 shortblock from FFHP before they went under. I checked out everything on it today because I'm thinking about putting it together. What I have found is that it has a Eagle crank 4.00 stroke, Compstar 6.125 rods and Coated top Diamond -2cc flat top pistrons. What I found seems to me a little out of the norm. The piston is out of the hole on tdc by .025. I plan on running a Cometic head gasket with a compressed thickness of .055 and I'am looking to run 250+ HP of nitrous through it. I do not like the tight quench of .30 on the bottle. I spoke to Diamond today who gave me 2 suggestions. 1. Mill .015-.020 off the top of the piston and loose the coating. or 2. Go to a .074 Cometic head gasket. What would you do if you were in my shoes?

 

i would run the .074" gasket, i wouldnt mill a piston you plan on spraying.
i think cometic makes a .060" gasket, which would give you a quench of .035", which is acceptable

 

Definitely the head gasket thinkness ++++. I would not want to modify a piston more than I had to anyway. Plus you lose the coating.

 

How did you measure the deck height? Did you rock the piston and measure the high point, or average of high/low?

Kurt

 

Yes I rocked the piston up and down and got an average of .025 out. I thought that I should run a little thicker head gasket to make sure that under 250-300 hp of spray;that I have that added safety. I ordered a .074 cometic.