I got the 99-00 Caddy front end conversion for my 91 Chevy step-side, can I leave the e-coat primer on the inside of the fenders or do I need to scuff them and put something on it? If I need to paint what should I use, I was thinking of just putting some undercoating to help deaden the sound, good idea?



Thanks,
Rock

Most body shops do nothing to the back side of the body panels. However it would stop rust if you painted it or under coated it.

Just sand it with 320 grit sand paper or use a red scotchbrite and make sure the entire area is scuffed good so that it isnt shiny any more. This will make sure the paint or under coating adhears properly.