Hey, my brother wants to know if it is okay to match port the openings of the coolant passages in the block to the coolant passages in the heads( make the holes the same size). The holes from the block to the head are a different size and he want to know if making the coolant holes in the block bigger will cause problems. Any feedback will be helpful.

Dustin

Shouldn't be necessary.
It would also be a b!tch to keep all the shavings out of the block.
I wouldn't worry too much.