68 cuda restoration

I have a 68 cuda that I'm getting ready to restore, I have been throwing the idea of either keeping her original or just upgrading her to a street rod. Right now I have a 225 slant 6 thats in rough shape and the brakes are shot. Everything is original and the body is in good shape except the trunk bed which has a big hole in it. I'll eventually put a new trunk pan in but I'd like to work on the mechanics first. I'm looking at replacing the slant 6 with a 383, if I go that route I'll have to upgrade everything and that'll get pricey fast. I could just drop a fresh 225 in and just revamp the transmission, this would be a lot cheaper but I would like to put some larger teeth in this fish. What do you think out there? Stay original cream puff or just go ahead and make the move toward more muscle?