VX blocks have the same rod lengths as normal D16's, despite being D15's. But they have the same stroke as a D15. What is the difference between a b7 and z1 block, I'm assuming the cranks are the same, different rods. What if I used a b7 block, (crank and pistons) and then just used D16 sized rods? I'm guessing the pistons would come out of the bore due to the extra length of the rod. So are the vx blocks way different? Deck height is the same. If someone understands what I'm talking about, enlighten me as to the differences. TIA