I did this with the 3" Rancho kit on my 86/87 trucks. Dialed in about 2" and it was great - allowed full compression on the trail at full speed.

IFS kits do not suck, despite some people with chips on their shoulder regarding them. The idea of beefing the kit with cross braces is a good one, but I'd make them bolt in to allow easier servicing of the diff should you need to do so in the future. Also, add the kicker braces from a pro-comp kit and a good skid plate.

Brian K. Gallus
I have nothing important to say.