One reason that you've had no responses is that you posted in the Archive. Several of the questions you inquire about have been posed numerous times and it'll be worth your while to search through this archive. The Diamonte is front wheel drive, not rear. There are many examples of the 6G74 from the Stealth or 3000GT being used.
1988 Mighty Max turbo 2.6 service body
1980 Power Wagon W400
Sundry Mitsubishi Montero Gen 1 parts
Parts vehicles: 1980 D50 2wd, 1988 Mighty Max 4wd, 89 LS Montero 4-door, 2002 Sport AWD
For Sale: 1989 Power Ram 50 extended cab