If you go for a 700r4 be sure you find an '88+. The 700 went thru a lot of development and the older ones are weak. You may already know that. You may consider stepping up to a 4L80E tho if planning on modding the diesel or towing. I think most of us with thought time about an SAS decided the stock rear axle is suitable for duty. Check the specs and you will see it compares with a D60 but you don't have to worry about cutting the axle width down or changing the lug pattern. I think you can still find a 5.38 r&p set to match the gears put into the D44 - check Independent 4x.com. An ARB should be able to be acquired as well, or an Aussie locker (bleh) could be used with an open carrier. There has been a lot of thought and talk on the matters of swapping stuff, from a diesel, a manual, a solid axle, an SBC... nobody has ever made any of it work yet. So hurry up!