Decking 452 heads on 413

Seen thread long time ago on maximun decking of open chamber heads. I am building a 413 for a friend and putting on a set of 452 heads for the hardened seats and unleaded fuel. The only pistons available without going to custom are Speed Pros with a compression ratio of 9.7 to 1, that is with stock closed chamber heads. By putting on a set of open chamber heads I believe the CR will drop to 8.5. To bump this up can we safely remove at lease .050 from the heads and use a thinner head gasket? This should move the CR to at least 9.3. Any info or ideas? Any other problems I need to look for in doing this? I'm sure others have done this already.This is going into a street driven car. Any ideas for a good camshaft to move up the cylinder pressure also? Thanks I want to do it right the first time.

No reason why not. Same basic block configuration as a 440. Make sure to mock up for intake fit before final install for intake fit. Taking .0123 off the intake side of the head for every .010 off the face of the head.

They say that .060 is max allowed milling on those heads. I cut a set of 452's .100 and made closed chambers out of them. It's not recomended but it worked for me, they still haven't cracked. Dave

Consider having the heads angle milled where the material removed is on the combustion chamber side of the head.I angle milled my 85cc 346 heads to 78cc and did'nt have to cut the intake or intake side of the head.I could have probably gone farther but the quench dome on my pistons would hit the head.
pick a cam as if it were a 440 and maybe go one size smaller for the 413 depending on the rest of the combo.

i promise you those untouched hardened seats after 30+ years are no longer doing their job.

I hear that a .050 cut will only gain you .5 piont of comp..

How far in the hole are those pistons you want to use? Also, why not deck the block as well? That way you don't have to take it all out of the heads.

Just in the early stages. I am trying to locate the pistons required without going to custom made. JEGS said there is no part number available through anyone they deal with, this may be a problem. The corner machine shop said they can get some from Speed Pro, so at this time I don't know how much in the hole they will be. I do know the motor will have to be bored oversize.

Don't know about the Speed Pro, but I did some calculations on what were advertised as 9.7:1 CR off-the-shelf 413 pistons a few years ago, based on the dimensions supplied, and came up with they were gonna be something like .080 below the top of the block at TDC.

Might be better to spend a few hundred $$$ on some custom pistons that actually fit like you want them to.