I have a 360 magnum that I am putting thinner head gaskets on to raise compression. It has RHS indy heads and dished ICON forged pistons. The pistons are 0.005" below deck and the gaskets I was thinking about running are 0.025" thick.
Here are the pistons Pistons

What is the safe limit for piston to head clearance?
Thanks

Hello Ori! .030 is pretty tight but could be done with tight piston/bore clearance (less piston rock) & carefull measureing & I'm assuming steel rods. Are these steel shim gaskets? Is the .025" thickness the listed or measured? It'd build up the height a bit & help sealing with some copper coat or aluminum spray paint. What's your SCR? Is the P/V clearance adequate?

.040" is probably save but it depends on piston rock,bore diameter & rod stretch,have read on moparts where guys have ran less and got away with it

Mitch

.030 piston to head with steel rods and reasonable piston to wall clearance is probably doable, but is it worth the risk & trouble? Assuming that you're using the typical 1008 Fel Pro's now you will only reduce the gasket thickness by .014. At best you will pick up .25 point of compression. Again assuming that your present static compression ratio is somewhere between 9.5:1 and 10.5:1 now it won't be enough of a change to show up anywhere except for maybe 5-6 hp on a dyno. If you're close to 10.5 now it just might make pump gas problamatic. If you're at 9:1 or less now just mill the heads .060 and you should pick up close to one full point which is enough to notice.

With steel rods I would say 0.040" is perfectly fine, 0.030" would probably be okay as well, but you're not going to gain enough in quench or CR to risk it.

IMHO it isn't worth it. 0.035 is the least I'd feel comfortable with. And that's with everything right.
Smack the pistons into the head enough times and they will fail and take out the engine.
R.