Piston and con rod dilemma

The KB pistons have a 6cc volume, 2cc less than the TRWs. so you will se a slight bump in compression. They both have a 1.840 ch, so your good there.

Your peak power is going to be under 7000rpm with that cam. You would need a minimum of 250* @.050" to get it to peak at 7000rpm or above. You can take it to 7000rpm, but you will really need to play with shift points. If you go to high, and bypass the torque you wont go any faster.