All the suspension pieces are interchangeable except the upper arm mount, it's wider.
Shocks and drive shafts are also common. The major diferences are the drive train/diffs and chassis.
PW has TQ'd and won every FORGASS State race he has entered with The R12. A TQ and second at our regions was due to a cross threded plug and an 11 lap later start, still got 2nd!
He was also faster than Barry Baker at a local race by 2/10th per lap until a glo plug vibrated loose and and he had a 191 second lap. He un lapped him self past Barry 5 times to finish 3rd.