Hello everyone. I have been doing extensive research on swapping vortec heads onto the TBI 350 in my Caddy (in signature). While doing research, I was led to this site. My biggest hesitations with doing this swap are: not making the car run worse, not dealing with a check engine light, and not getting buried and overwhelmed with details like making a custom EGR setup or eliminating it altogether and tuning becoming a nightmare, not hurting gas mileage at all or too much. Anyway, I am a mechanic by trade, and thus very capable. I have a few other toys too including a '69 GTO project car, an '86 F150 Flareside 4x4, an '02 Harley Low Rider, a '71 M35A2 deuce and a half, and an '88 Baja Sunsport. My Caddy is my daily driver and my baby. It's a great cruiser that's just a little short on power. I get about 12 MPG city and 18-20 highway. I'd love to get some help getting the Caddy some more power. I want to retain the TBI EFI and swap on a good set of vortec heads I have. I don't know if I should make a separate thread for that in the GM EFI section or delve right into it here.