which kbs???

KB107 flat tops with typical unmachined block (0.012 to 0.018 in the hole), 72 cc open chamber 340/360 heads and an 0.039" thick head gasket will yield a compression ration of around 9.3:1.

To get to 10:1 you will need to machine the block for zero deck or have 65cc chamber heads which would also take a lot of machining.