question about how shops do this....

Im planning on replacing my stock exhaust (cat back, which on my car is actually header back) with a custom one. do most muffler shops use crush bends or mandrel? Dont they usually have a bunch of short peices from which they trial fit and weld together until its done? im assuming they will recommend an inline muffler (before the rear muffler) to quiet the exhaust down a little bit. is it expensive for them to weld a flange onto the new piping and taper it to a larger size? (from the header size to the 2.5 or so pipe i want to put in.)

crush bent wouldn't be any better than stock. A good shop will use small pieces to create an outline for mandrel bending a new piece of pipe. Flanges cost about $5 each.

A good shop will use small pieces to create an outline for mandrel bending a new piece of pipe.

if they can, a crush bender is cheaper then a mandrel bender, and as such are more common unless the shop has the extra money. ask the shop what they have.

In my experience it seems like about one shop in ten has a mandrel bender. The shop that I use here in L.A. is a high-end custom and resto shop and they don't have a mandrel bender, but they will farm out the bending to another place if you request mandrel stuff.