Where is the best place for parts? I have a 340 Magnum all numbers matching. I need a trunk pan, both sides and center. Mine has several pinholes. I also need an antenna assembly. Everything else is fine.

 

there are a number of good sources i've come across, just shop around them a bit for the best prices on parts (there are big differences sometimes) try:
www.jacksautoparts.com
www.yearone.com
www.jimsautoparts.com/store
www.goodmarkindustries.com

there are others but i've ordered various pieces from them and have been quite pleased with the results

 

Steer clear of Jim's Auto Parts. Service is terrible, frequently he doesn't have what he says he does, and has ripped people off in the past on both shipping and the prices of the parts themselves.