I looked in every salvage yard i could find and could not find a pontiac with a 3.1 they were all like 2.4, 3.4, or 3.8. The malibu motor looks almost identical and they both are GM so idk what to do. It only 375 for the motor and i actually heard it run unlike most slavage motors.
It doesnt matter if its chevy, buick, olds, pontiac, etc, they all used the same 3.1 engines. Generally speaking, the only differences were accessories on the engine, and there were a few versions of the intake manifold. Look for any engine with the vin code of "M" (8th digit in the vin #)