'1967' 440/375 HP and 440/350 HP Comparison

My question is, my 69' 383 HP block is 10.1 0r so, and I have a new set of 915's. The piston appears to be flat top, but very close. I would like to use them on the 69'. What will it do in that application? This for my 69' 383 Cuda, stock manifolds. Sorry for a repeat question from above. My 915's have the large exhaust valve. .