HaV

you shouldnt notice any difference at all other than sound past the muffler if you used the same diameter piping.... the air discharge, back presure, etc is all determined post muffler by the size of the outlet and the piping connected to it.. doesnt matter how far back it goes.. just the diameter.

and even if its just slightly more restrictive or slightly more open, it shouldnt do anything... your headers, cats, mufflers and pipe diameter make the difference in your exhaust flow.. not really the length /angle of the piping after the muffler. Only thing that should be effected is the sound.