I was going to weld up some exhaust for a kid and his chevy but he backed out. I have all sorts of mandrel bent pieces but they are 2.5 in. Can I use it to modify my Starion and use the rest to make my IC system? Will pressure drop be that much? I just got my SAFC and saving for injectors but I'm only running 5 lbs. now anyway. Thanks.

Granted 2.5" is on the large end of things, but you should be fine. I've noticed other stock turbo people run their intercooler piping at the same diameter, so you should have no concerns. Just make sure to modify your endtank inlets to 2.5" as well.