Hp Questions

KB107 pistons are a very good low cost performance piston, much stronger than stock cast but not as strong as forged. If you go with them absolutely follow the instructions for ring gap.

In an un-machined block and heads the compression will wind up in the low 9's to 1. Having the block machined for zero deck and you can have around 10 to 1. The KB's are much lighter than stock so at the very least you will need to have the rotating assembly balanced.

IMHO, if you are going to invest a $200 in new pistons and another $200 to have the balancing done I would also have the block bored to the first oversize and the block decked.

With the other parts you are likely talking about 300 HP.