typical rebuild should be only seals, bearings, and ideally the three synchro rings (approx $23 US each).
A kit with koyo bearings will suffice.
I was told by the importer of many of the rebuild kits to the states, that the aftermarket synchos suck and to use only Toyota- for a H55 all three are the same part number.
The key to cost effective rebuilding is the 1st gear synchronizer ring which manual show how to measure slop (big slidey thing in rear of transmission within case). If it is out of spec, costs in US dollars exceed $350 discount rate. It is my belief it's cheaper to buy a new transmission than rebuild in this event.
forks, gears, etc if needed drive the case cost even higher. It's a push to replace the 5th gear unless you can score a Seamaster at a good deal.
If you can get a compatible year used tranny from a wrecker, the input shaft can be swapped replacing 2 of the 3 synchros, the two counter shaft bearings, the input roller bearings, and the rear output bearings, 2/5 of a standard rebuild anyway.
(to be confirmed) the H55s 1983-1986 transmissions are the same internals and the 1986-1999 are the same. Inputs can go back and forth without issue in same years.
FYI: In the states, a late model H55 (gasser/2H) is about $1,600-$1,650 new in a Toyota box.
