I did the Chevy spring swap using a 3 spring + overload pack and took the overload out so I have no problems with the e-brake cable. I didn't have to shim, my pinion angle was right on the money (about 2 degrees off in the rear, so while under power it should be perfectly parallel with the transfer case). There is no driveline vibration.

At first I used a double shackle setup, but after everyone got me worried about using double shackles I switched to a single shackle using the existing rear shackle hanger. The shackle is pretty laid back, but the truck rides fine and flexes good.

'89 4Runner, 22RE. Chevy spring swap, 8,000 lb Warn winch, custom front and rear bumpers, e-locker rear. Saved by Grace.