Max compression for pump gas iron head

I was planning on using KB167 pistons but with the 59cc heads and after square decking the motor it looks like I would be over 10.5 to 1. Based on that I think I will use the 89 318 pistons which have a taller compresion height than stock and are cast not hyperuetectic. I wanted to get over 10 to 1 and less than 10.5 to one if you guys think that is reasonable. The 302 closed chambers are supposed to be a little safer with higher compression is what I was told. The cam will be the Comp 268H with springs lifters and a new timing set up if that matters. thx