Sorry for the # of posts, but I keep thinking of things.

The #1 problem the we all encountered with SAS is the front drive shaft. They are very short on the isuzu. Every one who has built with a low pinion axle has had a devil of a time getting it to work properly. Until I designed and built my dual t-case set up I was spitting shafts every time I went out. The dual case completely solved my DS problems, but I have wheel base to work with on the trooper. A linked front end will help with DS issues and will reduce the plunge on the DS. Rear mounted shackles on leaf springs would be the worst as far as plunge goes.

Using a HP axle solves half of the problem right from the start. I know that it increases the up front cost, but in the end you may save $ because you won't have to build aroung the problems a LP axle creates.

One possible solution is to do what I did on my axle. I started with a chevy d44. I then cut off the knuckles. Measured and shortned the tubes. I then gound down the knuckle welds and pressed out the cut off tube section. Then I put the knuckles back on and rotated the pinion up about 20*. I chose to match the width of my rear axle at 59". The downside is that I have a custom long side inner shaft. I use a waggy short side inner shaft. In retro spect I would have gone with the waggy width on both sides. this mod essentially raises the pinion up to around HP axle height, and releaves u-joint angle at the axle end. Your only extra cost would be to pick up a chevy d44 housing to modify,I bet you could find a free housing if you looked around.