I have 96 Bronco with 5.0. Currently it has the 5 speed tranny (the same ones they but in the mazda pick ups) I was wondering what the best tranny and t case set up would be to switch to an automatic transmission. i currently have the manuel t case, not electronic, and would like to keep it that way. Any help would be greatly appreciated
Your best option is probably going to be an AOD. The C6 is great and very durable but the addition of a 4th gear will make a huge difference in your mileage and with fuel fixing to hit $4/Gal I'd give that a LOT of thought. E4OD's and AOD-E's are the next evolution of the AOD but if you use one it will require a processor to control shift-points and torque converter lockup so you'll have to either retro the EEC computer from the donor truck as well or add a stand-alone processor like the ones available from Baumann Electronics
http://www.baumannengineering.com/tcs.htm .
The T-case will bolt right up but DO be sure to get a tranny from a 4x4, I only add this because I actually know a couple guys who went & bought OD trannys only to find out halfway thru the build that they had 2WD units and that just results in thrown wrenches and wasted $$$. You're also going to want the transmission crossmember from the donor because it'll save you a lot of time in modifying/fabricating something on your own.
The AOD's are VERY sensitive to the throttle pressure so once it's in either have a shop adjust it or do it yourself but it *needs* to be done because a misadjusted TV cable throws the throttle pressure out of whack and that probably burns up more AOD's than anything else. Also, when looking for donors you'll want an 88' or later AOD if possible. Ford made a lot of running changes to them over the years to address various weaknesses and any post-88' units will have all the upgrades already in place. Any AOD that's rebuilt these days is rebuilt to 88' specs.
Consider yourself fortunate to have a manual T-case (the last article I can recall reading mentioned that by 96' something close to 80% of all Broncos delivered had the pushbutton electric T-case instead of the manual. You almost had to *order* it to get one). The 1356 is a decent unit and unlike the electric versions there isn't very much there to go wrong on yours. If you're under there and working on it I'd take the opportunity to drain the ATF in it and swap to a synthetic fluid. Synthetic ATF will not only make shifting it easier but it will do a lot for the longevity of the thing. Since it only takes a few quarts you're looking at less than $30 to do it and the benefits of switching to synthetic are WELL worth $30.