The simple answer is yes. It's going to move in every direction. Fore/aft should have the least movement of the mounts are in good shape, but when you're pounding around on the trail the drivetrain will move an inch or more in every direction.
Just ran across this while looking for info for a customer. To add another data point, the www.stinkyfab.com shackles have 2 mounting options, 5.5" and 6.5" long.
The problem is, it's next to impossible to prove that they used the wrong oil. I saw what came out and it was like water, but when it comes right down to it cal is in a he said she said situation. He knows what he gave them and knows what came out didn't look right, but if they say they put in...
There is more to update but I've been a bit behind on posting. If you go to the stinkyfab racing YouTube page i posted a couple build videos on the motor. I also designed a new transmission pan skid that will be available soon.
You sir are 100% wrong. Caster absolutely can and will cause death wobble all by itself, even in a brand spanking new car. We can grab a JK off the dealer lot, adjust the caster and it'll shake the poop out of you. With old XJ's it's absolutely most often a combination of issues, but it doesn't...
In a perfect world you'd have the pinion in line with the driveshaft, and the proper amount of caster. In this case you can't have both (not easily anyways) so you deal with a less than optimal pinion angle so that it'll drive without being a safety hazard.
LazyXJ though you are correct that many times DW is caused by worn parts I can assure you that even with EVERYTHING brand new you can get death wobble simply from having the caster out of whack. When I first got our shop comanche I replaced every piece of the front steering and suspension system...
First, the t-case drop isn't doing your front driveline any favors. You're far better off with an SYE and no drop. I'd say you still need a bit more caster. Generally speaking having the top of the axle rolled back 5-8 degrees is the working area. Too much or too little will give you a case of...
I know you seem to be wanting ideas for doing it yourself, but there's also the option of making it easy on yourself and just buying some brackets.
http://www.stinkyfab.com/sfr-jeep-xj-cherokee-long-arm-brackets/