5th Gen ('95-'99): 3.1 vs 3.8
It would add a lot of power, even for the NA version. The NA engine is about a 40 hp / 40 tq gain. On a 600 hp car, that may not be particularly noticeable, but on a sub 200 hp car, that's a major delta. I'd guess you'd shave a full second off the 1/4 mile time.
Not to mention, getting that kind of gain by modding the 3100 would be incredibly difficult.
With that said, I don't think it would be remotely worth it to swap now, especially if you were only going to do the NA 3800. 5th gen montes are dirt cheap. I can't imagine a 5th gen with a 3800 in it would cost more than a couple grand. By the time you bought an engine, trans, wiring, and spent the labor putting it in, it wouldn't make any real sense to do the swap anymore.
Heck, you could pick up a 3800 grand prix or early 6th gen monte for not much more money since the values are all pretty well bottomed out at this point.
Not to mention, getting that kind of gain by modding the 3100 would be incredibly difficult.
With that said, I don't think it would be remotely worth it to swap now, especially if you were only going to do the NA 3800. 5th gen montes are dirt cheap. I can't imagine a 5th gen with a 3800 in it would cost more than a couple grand. By the time you bought an engine, trans, wiring, and spent the labor putting it in, it wouldn't make any real sense to do the swap anymore.
Heck, you could pick up a 3800 grand prix or early 6th gen monte for not much more money since the values are all pretty well bottomed out at this point.
Oh, you'd be shocked. A local dealer here has an absolute base 3800 NA 04 Grand Prix (we're talking cloth seats here) for over 6 grand.
