anyone running sidepipes?

i have a 360 in my car with header's. i'm guessing they are Hedmans, but they could be anything. i'm thinking that i'm going to have to get a local shop to hook them up and make the "S" bends and connections for me. the ones listed have a 2" or 2 1/4" inlet, but by the picture it looks to neck up to 3". i'm thinking the "S" should be 2 1/2" and they can cut the inlet of the sidepipe to match.
how do they attach to the car?
my car has a very lumpy cam and the engine shakes ALOT, is this potentially going to be a problem with the joints in the exhaust connections?
is there any baffles inside the pipes or is it straight through?