I just wanted to check if any one knew what I need to R+R from this engine swap. 1997 GP To 1995 Bonnevile? I got the wiring harness from the GP and was wondering if that to has to be Changed?? It does not look exactly the same.. HOw about other things? I know the motor mounts have to be changed. HOw about the exhaust manifold? Any help would be greatly appreciated.

The 97 will have a MAP sensor that your '95 does not.

The outlet of the rear exhaust manifold is in the wrong location. You'll need to keep yours. You'll also have to swap over your accessory bracket. The GP bracket is different.

The wiring harness is different because your PCM is in the passenger cabin, and the GP is not.

Where is the map senor on the Grand prix engine located and does it have to be removed to wire up to the 95 Bonneville?? Or is there different type of sensor there?

One more thing, Do I have to chane just the rear exhaust manifold or front and rear?

The map sensor on the gp motor is located on the pulley side of the intake manifold. The 95 will have a cap in the same location. Just swap it over.
It'* not so much that the outlet of the gp exhaust manifold is on the wrong location, it'* that it will not bolt up. I tried it, the gp down pipe is different and the bolt pattern is different by a 1/8" or so. So, you will have to swap out only the rear to make it work.
Also, the wiring harness, oil filter adapter, mounts, accessory bracket, and throttle body are all different.