I have alot of experience with the C5 and installing performance parts. I did a motor for a customer here at work. West Coast Corvettes has a kit that comes with ported heads, polished valves, cam, headers, computer, intake. It was a good conversion. The engine suffered a little on the bottom end, but the top end and RPM really picked up. I did another with only bolt ons. Intake, headers, X pipe, and a Yank 3500 stall convertor. This car was amazingly quick. The Yank torque conv. is just awsome. This was a 2001. It ran 11.93 in the 1/4 with a stock motor!! If you have an automatic the convertor is a must.