I would have replied earlier but it's been a busy few days loading trucks at the farm.
Paul, your correct, I am going to have to drop them a little. According to the measurements I took when I flexed it they will be about 4" away from contact. I haven't decided if I want to play with the back to see if I can get a little more flex out of it. For now their on but yet to be finished.
Yes brad I am using the factory unit out of the 88. I figure if it breaks, I have three more to improve on design
I'm also cheap. As it sits, not including the tires, I'm a little over $900 into parts and materials on the "new build"; purchasing a fixed yoke case just adds $$ to the bill.
As for the cases. Factory length mua5 bellhousing edge to tailshaft tip I measured 37 1/4". The rear case adapter edge to flange I got 18". The front case has 4"" of output splines, the rear has 2 3/4" of input splines. Slid together with full spline engagement and the front case tailshaft trimmed 1.5" output splines untouched the unit is 50 3/8" long. That's only 13 1/8" longer then factory.
First things first pulled the rear half. Brad has a few threads that ALWAYS come up in my searches, they are filled with helpful pictures and tons of information. Thank you. Being able to see the things in pieces, and usually a write up that is generally a "how to" it makes the task feel much less daunting.
I haven't actually gotten to any gear pulling besides the front cases rear output but I did some cutting
Now there are options on the horizon. In the photo below the piece I cut off is sitting on top, and the white line on the splines is full engagement, there is 1.5" excess below the line. The area the punch is pointing at is where a 1/4" plate would mate on the housing if welded to the adapter- only cutting being the front case rear housing- there is 1/2" space between the housing end and adapter seal. The cast ring below the punch is the area where the tailshaft bearing with seal seats.
The area below to the right is where the case bulks up and the speed gear bolts in. Given I don't need that on the front case deciding how much spline engadgement and cutting I want to do will determine the overall length. The case is faily thick but the farther I bring it forward the stronger I think it would be, however if I ever break any internal hard parts(front case output) it will also require modification to replace. That isn't the end of the world.
This is a photo of the unit slid together(only front case output housing trimmed 1.5"). Measuring tape gives a rough representation of how much I can shorten it up between the cases. If I get some time this week I might play with it a bit.