I have a set of pistons from A&I. They are conformatic pistons. Where the flat part of the piston meets the flat part of the head,(8060 gas head anyway) there is raised lettering on the piston that says "front" with an arrow. When hot, this raised lettering would touch.
I would have the raised lettering milled off.
A good rule of thumb is to put the head on the block without a gasket and turn it over. If it will roll over without lifting the head, then you are good. The stock gasket is about .065 - .070". That clearence will likely be reduced by .020" when hot.
With the 8060 head milled .050", and those pistons, I have 150psi and it likes 91 octane fuel. You will likely need 93 or better with your LP head.