not sure how to tell..dont know much with engine and other parts haha
get down and look under the truck... you'll wanna be by the bedside next to the cab.
the one piece is a big bitch that goes from the trans to the rearend.
the 2 piece goes from the trans to a crossmember, then down to the rear. the driveshaft will also be a lil smaller as well.
and if he complains... show him this. for size reference... the rims are 18s and the total wheel height is 25in (97 CC v6 sport)