By all means keep the press fit wrist pins as Pat says. To put slip fits in you will need to install bushings and drill a lube hole or holes in the small end. It will probably be more cost effective to just purchase new rods with slip fits if you are determined to have them. The only reason I could see for using them would be if you are going to be replacing pistons or rods later on.

We always used slip fits on the racers but they had aluminum rods. You use all the zippers you can when you toast a couple every pass.