so yesterday I got some nice bilstein shocks at a swap meet for $5 and decided to throw them on and I put on the 6.5 inch shackles I had laying around today to go with it. My shackle angle now is almost vertical and my truck is hardly flexing better than stock. My cousin has his stock rears out of his 89 that I believe are 3 inches longer and that should give me a better shackle angle, correct? What my question really is, is that by moving my axle 1.5" back would it cause any driveline, suspension or brake problems?
Thanks,
Marshall

 

79-88 rears are 48"
89-95 are 51"

You will need to relocate the spring hangers

 

if you only move the rear shackle mount back you will need to check to make sure you have enough spline contact in the DS slip yoke. 4crawler has a DS spacer avalable on his website. it will also look kind of funky, the rear wheels will not be centered in the wheel well.
by not moving any of the mounts you might be able to get the springs in there with the longer shackle but the rear shackle will probably end up almost flat...

 

Well I looked on pbb and my axle would only be Moved back one inch and measured back 3 in inches from where my shackles are now and it would give me the perfect shackle angle I'm probably gonna do the swap this weekend so I'll let you guys know how it goes