Hey Rosco, time to share.
The old Coasters were identical running gear to the Dyna; that is pre 5 stud wheels.
I will be using a HZJ75 high pinion front diff, this will accept the Hilux bellcrank which avoids the complexity of using the 40 style frame mounted bellcrank.
75 diff is 4.1 and the rear will be a (forgive me) N****n H260 from GU leaf ute; the full floater at 4.111 - a bit like the old F250 with 4.10 rear and 4.09 front.
These N****n diffs are supposed to have a good LSD guts, but what about the transmission? GQ Patrol 4.2 iron case 5 speed can be converted to column shift using bus parts, and are almost free.
I hope too much N****n stuff won't get me kicked off the forum, but there is no way to fit a decent 5 speed Toyota box with column shift - the R151 is in my moderately experienced opinion only good for a truck to one and a half tons.
My truck is powered by the high torque baby Buick - the one with the pipe headers. The box I have run for the last eight years (the "long hat") has a 0.75 over fifth which is asking a bit much, the N****n box is 0.85 so she should cruise nicely.
Front is already spring over as 2WD with 3' drop beam, and leaves are dead flat - just gotta flip the rear perches, this will give a lift of five and a half inches....please pray with me to pass the Moose test (swerve test in Aus).
I'll be happy to bop along at 55mph anyway - the places I go aren't going anywhere soon...