BTT.
I went with the Ford Racing kit. It includes the 6 pinion first gear planetary, and a 4 pinion intermediate planetary, along with torrington thrust bearings replacing all the regular flat thrust washers.
You get 2 big improvements:
1) low first and second gear, along with lower reverse- effectively widens the gear ratios for a 'wide ratio' gear set.
2) roller thrustwashers reduce heat and free up power that is otherwise spent trying to turn the gears under load.
It's not really that expensive when you think about the advantages. Since the parts are from an E4OD, you 'could' do the conversion yourself. It's pretty much just parts swapping. I did the FRP kit becuase I could not find a donor E4OD and the parts from FRP are brand new.
I also did some other mods while building the tranny:
installed 5 disc forward and low gear clutch assemblies.
installed a lower ratio intermediate lever (can't remember ratio)
installed Art Carr reverse manual VB for offroad with compression braking
I have run this engine/tranny combo about 6 times now with last one being Las Cruces. The tranny has worked pretty well. I think I have a problem with the intermediate servo- it sticks some times and will cause a brief lock-up ccondition when upshifting from 2 to 3, and back down from 3 to 2. It climbs great. You only have to very lightly tap the throttle to pop over a big rock. With steep ledges, just rest foot on throttle and apply a some light braking to load everything up and it just creeps along.
It does shift hard from 1-2, hard enough to bark the 39s under full throttle on the street in 2H. The lower first gear combined with the 5.13s has enough off idle torque to spin the 39s from a standing start with no power braking. With engine idling in first gear, just take foot of brake, stomp the throttle to the floor and you get about 10 feet of tire spin until they hook up. Not bad for a dinky 5.0 not getting any boost until about 2800 rpm.
