are 12v and 24v blocks the same?

I bought a used 53 engine for cheap. I have a couple 12v blocks that I was going to build later for projects, but I really want 24v P-pump. Can I use my 12v block with my 24v internals? Block is decked and crossthatched already, I will just need to re-ring the pistons and rebuild right?

Thanks for the help

Chris