3.1 engine swap
 

I have a 99 Monte ls and the motor is hatched. I have a donor that is an 01 Buick century but its not a direct swap. Anyone know what I will need to change to make the century motor work in the Monte?

Depends what engine is in the Century

Probably axles, PCM, wiring harness...IDK if a Century motor will bolt up to your mounts either. I know a Regal motor will FWIW

Basically, keep you Monte's trans (so you don't deal with PCM and axle issues).... Use the Monte's wiring harnesses. You will probably need to swap the motor mount brackets and some sensors.

Only way to know for sure is rip into. If you wanted to up the performance while doing this swap, getting a 3400 to pop in place of a 3100 would be the way to go. The N-body guys have a right up to assist with some of the "need to knows"....