Sorry I didnt answer your post earlier.
But the 3300 wont work with the 95 PCM.
You are going to need a manual for both engines preferably so you can figure out what wires are needed to get it running.
The 3.3 is WAY different then the 3.1, and I doubt the motor mounts will line up and the trans might not bolt up either to the 3.3.
3.1 is a 60deg V6 and the 3.3 is a 90deg.
You are going to have alot of work ahead of you.
And this is something I have not done before.
But I did swap a 95 3.3 Old into a 93 GA w/3.3 back in the day.
It alone took me several weeks to get tuned/running what a head ache
Your best bet is to get rid of the 3.3 and get your self a 3.1 , a 3.4 would work too but you still would have alot of work and someone with a Tech II scanner to program the PCM.
Good Luck!