Rebuild
If you going to do a rebuild and want some more power a good port job will do that. however the only thing that is being ported and/or polished is the ports and/or combustion chambers on the heads, also posbaly the intake runners on the intake. You can run a diffrent pistion that will bump up the compression ratio. This will make more HP, however to much on low octane fuel will cause pre detination(Knocking)
As said do some reading. 450 HP(rear wheel) Is not that easy to achive naturaly asperated, especially if you want to keep it pretty streetable. First need to figure out what you are shooting for and what your budget is. Then how advanced you are on working on your car. This is a key factor when figuring budget.
You have some SERIOUS reading to do, someone is trying to take you for a ride, do you know what a piston is? Why do you need a rebuild?





