trash the motor, get a C5R block and make a 14:1 427...............ok, maybe not.

i also have seen more performance increases with even a light computer tune. tune gets my vote too.

a cat-back wouldn't hurt either and would sound really cool. of course a K&N would be nice and you would never have to buy another air filter, just get the Gen III kit if you do or something similar.

 

Dont try to break in your motor with synthetic, it wont. Let it go till the engine oil monitor says its time for an oil change, then swap out the oil and filter for synthetic.

 

get the intake done and tuning, makes a big differance. then find a good cat back to buy or get a custom one done.