[ohenry5]

Well if you wanted to upgrade the engine you would have to upgrade the trans and everything. Plus it would be a tight fit for the larger engines and they might not fit, actually you would have to modify the engine mounts because on the other engines they do not have the same mounts as the 3.1L. You could have the 3.1 rebuilt with a new block, they are usually very good after a rebuild, or you can get one from a junkyard that has low mileage. Well hope that helps.