Yea, its always a good idea to hold the old part next to the new one before putting it on if you can. The one you got might be for one of the front wheel drive variants of the Mitsu 3.5/3.8...in which case the acc. bracket is probably quite a bit different.

99 Gen 2.5, fixing blown head gasket
89 SWB- 33's, ARB Front locker, SR rear locker/axle, SR F brakes, winch, WST Offroad Armor all Around, 2.85 Aussie T-case Gears (SOLD)
Sold: (2) 95 SR's, 86 SWB, 90LWB, 91 LWB
-Can Change a timing belt in my sleep..