Bought a canned PCM for a GT.
Was not worth it at all.
Did an intake, equally not worth it.
Put headers on. Only thing I noticed actually made a difference. It moved the powerband up. If that's not what you're after, perhaps a plog and downpipe might help while keeping the powerband from moving too much.
I would leave it bone stock. Maintainence will likely keep your hands full. For starters, you'll want to replace your LIM and valve cover gaskets including the coolant elbows and a new UIM. At the very least, check to see if the LIM gasket is plastic or metal. If metal, it should be fine. If plastic, change it before it causes you problems when you don't have the time for it.
