All-Pro Off-Road makes some real nice stuff too. If you get some weld on shock mounts for the bottom, you should be able to still use the upper stock mounts.

http://allprooffroad.com/index.php?option=content&task=view&id=49


91 SR5 Xtra Cab, 298000km, 4" lift, 56" rear springs, 33-12.5R15 BFG Mud-Terran T/A KM2.....and an '85 axle still waiting to go in.