I was thinking you had an MT. Yep, I think you've got alot more room to play with an AT.
On the pumpkin I was thinking that the high pinion would cause the driveshaft to slide out of the T case a little farther. Doesn't the companion flange sit about 2 inch higher? Of cource this my not be of any importance since the driveshaft does have to move with an axle.
After I win the lottery I'd like to go for the 4.9s , too.
They would come in handy at Garcia Ridge. Just not to sure if this high pinion would work , leaving me with no optional gear choices.
I'll have to check Alldatapro at the Lib. to see when 4.9's started in the M.S.. I'm thinking with the idependant rear suspension 00., possibly the 4.9 only came with M.S. 3.5 SOHC engines. Lots of unbeatup 4wd M.S.s that are only used as soccermom mobiles.

dave h.
'89 Raider V6 5spd;Aisin Hubs;; Gen2 LS: frt. brakes, rear coils;U.C.arms;R.trailing arms;idler arm; rear LSD axle w.disc brakes ;2 battery system for Dog's fan; relocated ECU; custom bumpers;J.Baker receiver;Conferr roofrack; t-bar crank.