You can get a Supra LSD, they will fit in a 2WD axle. But you need to have a 2WD axle with an 8" ring gear. There is no LSD that I am aware of for the 7.5" ring gear.
Detroit True-Trac. Only LSD for the 7.5 There is a small bearing and big bearing one, i think the mini rear axles use the big bearing. -Ryan