[hardline_42]

Matt, how much compression are you after? If you keep the stock dished pistons and only upgrade to a 64cc head you're up approx. a whole point in compression. You have a little more wiggle room if you play with the quench height (you can modify a 0.015 shim gasket for a 350 to fit a 400). If you really want to run higher than 9.5:1 compression you can either mill the heads or swap out pistons, but remember either way you go won't be cheap and it won't be easily reversible if you find out it's not what you wanted. If you go the piston route, you might as well redo the whole bottom end while you're at it.

Also, about the post by SlowZ that you quoted above, it's worth it to find out a few things. For starters, climate and elevation have an impact on how much compression you can safely run. How far above sea level is he? What temps is he running in? Also, why did the engine blow up and why does he (or his friend) feel the need to pursue a different engine instead of rebuilding that one? Just a few things to keep in mind before taking it for granted that 10.8:1 is safe to run on pump gas.