Those are high compression and very heavy. like 11.5 to 1 or more compression depending on the chamber volume. I'd consider having the domes machined down to lower the compression and lose some weight, or trade them for some lower compression pistons. Better have some race gas if you decode to use them as is, and plan on head studs/o-ringing the block. Small blocks with 4 head bolts per cylinder don't like high compression without some help.