TBH I never really had much trouble with boxes ,my friends got a gearbox machine shop so that helped but i went through a bout 3 if i remember right .All had enlarged bearings and a late type case if i remeber right dunno,i shattered the crownwheel 2 times split a lay shaft,IMO Get 1 of bernies boxes there shot peened on the gear set i would imagine see how that goes i bet he alters the oil feeds also ,may have to buy 1 to open and have a look pmsl lol
Only jokin Bernie