the .15 or the .15Pro in most cases are not interchangeable with the 2.5s and the 3.3s, you ll need the new braces, drivetrain includeing shafts and cvds ect. the 3.3s and 2.5s are longer and a bit wider, thus to totally and correctly change over, you need the chassis, chassis braces, cvds, wide a arms, longer driveshafts, and in most cases motor mount too. it can be done. but needs more than just the chassis and braces or you ll end up with the Jonny Cash Song, "I got a 55 56 57 58 59 60 Cadillac aoutomobile"
Timmahh