I know that in 1980 you could get the Monte with a Buick 3.8 turbo in it, the same one that was in the Regal Sport Coupe. A 3.8 with a Rochester 4 Barrel, 350 tranny and open rear. Hot Rod magazine had a article on it, they opened up the exhaust, air filter, modified the carb with bigger jets and something to the linkage.... to make the butterfly valve go more vertical at WOT, added a shift kit to the tranny, water injection, up the boost by cutting the rod in half, lob off a 1/2" and threading the rod on both sides with a 1/4"-20 die nut and add a coupler nut to allow for more boost. Added a "dial a boost" bleeder valve to the interior, right above your knees, to control boost from the drivers' seat, added a boost gauge, dual exhast from the cat back.... think that's about it, I did all of these things when I was a senior in high school to my 79 sport coupe. I was able to beat my friends V-8 350 firebird every time we raced, not saying much but back in the day it was a lot of fun.
So back to your question, you could drop a 87 Intercooled motor in there and it will bolt right up to the 350 tranny, motor mounts wouldn't be a problem either.... good luck.
Chuck