looking for tighening specs for the leaf spring UBolts

i have a '73 manual it says 45 ft/lbs at the end of the chapter on rear springs.

1 ton B-300 with dana 60hd

if anyone has an '81 manual could you check for me.

If it has 1/2" fine threaded ubolts the spec would be the same as another vehicle with them & 45 sounds right iirc and I would assume they are the same dia between the years/app you listed. I would clean the threads & I oil em with 30 wt eng oil then blow em off with shop air. reportedly Ma's specs are for dry threads and using any lube you would reduce the spec accordingly depending on the type of lube but this is the way I do it & good so far.