quick question, wots size is the stock exhaust piping on a 3.5 TH??

It's just under 2.5". 2.25" - 2.4"

cool thx, i just booked my car in at carline mufflers, im gettin a custom 2.5" cat back system with a lukey LR2779 on the back for $270 so i was just making sure i was going up in pipe size, so thanx again