You can go up to 4" before problems begin, as long as you think through the entire process first.

You will probably want to convert to hy-steer at the same time. This alleviates the height issues, and eliminates both the torque rod, and bumpsteer.

If I remember correctly, Rough Country = Rough Ride. Pay the $$$, and splurge for the Alcans. A little spendy, but worth the peace of mind. Broken leaves suck.

Your front driveshaft will need modification, as your lift should allow more flex. It will need to be lengthened, and longer splines would be needed. The double-cardan joint should hanle the lift fine. The custom shaft would add another $100-200 to the project.

If you lift, you will also need new brakelines, a longer LSPV bracket, and longer shocks. For more flex, change the front to Ford shock towers, and add more angle to the rears.

Plenty of lift info here. Do a search.

"A young man who does not have what it takes to perform military service is not likely to have what it takes to make a living." - John F. Kennedy

Proud owner of an 88 Montero (with a blown engine).