Hard parts like pistons, Rods, and etc are not something you can do any time you want, like intercoolers. Also the pistons are the weakest part of the motor so why not replace it if you can do it. In addition they are cheaper than intercoolers. If you want to go cheap that is. Also I would recommend some rods Eagle Rods and some Weisco pistons (Z1 I think are good piston design) and you can get away with it cheaply and build the motor for whatever you will ever need to do and the new bearings and piston rings are a great idea to refresh the motor.
