I'm looking into which gearbox would be best too.
What about going to the dark side?
A H55F cruiser gearbox seems to bolt up to the Isuzu with a downey belhousing. Picture is at this link -
Downey bell housing question | IH8MUD Forum
I'm not sure what other parts are required ? Or even if a downey belhousing is easily sourced? The downside is the H55F only seems to have only been available with a part time transfer case. First is deep, but fifth only 0.845.
4.843:1 2.619:1 1.516:1 1:1 0.845:1 4.843:1Maybe other Land Cruiser gearboxes bolt up to this "downey belhousing" too?
Or a 440F auto from a 3F cruiser. The conversion from Isuzu to the auto is very neatly done here (almost seems too simple) -
Isuzu 4BD1T swap part II : now w/ A440F auto | IH8MUD Forum
The 440F seems to have pretty good ratios - 1st 2.95:1, 2nd 1.53:1, 3rd 1:1, 4th .717:1, reverse 2.678:1
Were the 4BD1T Isuzu trucks available with an automatic in Aus?
The 440F was apparently in 3F 80 Series cruisers up to 92 so should be available with their permanent 4WD transfer case. Also Wholesale Automatics do a heavy duty valve body
Wholesale Automatic Transmissions
I haven't seen anyone mention using cruiser gearbox/transfer cases with the 4BD1(T) before? Will they fit? Any thoughts?
Thanks Alan