If the short block is still together I'd measure the deck height & compare the OE piston compression distance to the CD of those 2 piston choices. If those heads are 302's I would shoot for .035"-040" quench which as you know will let you run the highest CR & fastest advance to get the most torque out of the lowest octane and when you choose the best pistons for this (I dont have an answer for your Q on that) then mock them up with a floating pin to find out how much to square deck the block to to get the CR/quench where you want it.