Disc brake rear for a V6 Mighty Max

[HandySmurf]

From my understanding and research, I believe my 5sp V6 4WD Mighty Maxs have 3.90 gears in them, use the larger 9 inch housing rather than the 8.5, and they are equipped with drum brakes on the rear axle. I would like to run disc brakes on every wheel when I put the project truck back together. I am already bending and flaring new solid stainless steel brake lines for the frame, and adjustable proportioning valves are available if needed, and as much as I feel I could make an adapter kit for the axle to be able to just bolt on new calipers, I would like to find something that I could just bolt in easily. I know none of the Mig. Maxs ever came with disc rears, but did a similar truck such as a Motero or Raider ever come with one using the 9" housing ?
Years ago I helped my friend install a rear disc conversion on his Tahoe, and I know it can be done rather easily with the right pieces, but I would like to be lazy and just bolt in what I want. Is anything like this available from any other straight axle model that anybody knows of. I have looked but I'm relatively confused (rather easily, sadly) so help from anyone knowledgable would be helpful. Thank you.

[pennyman1]

The 2nd gen monteros have 9" rears and disc brakes - I got one from a 95 sitting for when I get around to bagging and swapping motors. My rear has 4.625 gears and I really want 3.90 0r higher(lower numerically) for my 2wd 1980 D-50; 3.55 or 3.31 would be great, as the motor is a built Conquest 2.6 and I want to keep it in the power band at highway speeds. if you find a 95 and up montero, the parts should just unbolt from the axle tubes when pulling the axles. The backing plates hold the axle shafts and bearings in.