Unless you’re using original NAPCO, Coleman, or otherwise period correct 4x4 parts that fit right and look appropriate I think you should stick with 2wd. Those front axles may have limited gear choices, making for a slow truck.
Otherwise as Ed point out it’s a lot of work and may not look that pleasing.
If the truck has been in the family for so long drastic changes may be a mistake, it’s only original once.
If you only swapped the rear axle for a 14 bolt you’d have faster gear choices and readily available Detroit locker, might get by with 2wd just fine. Read sticky thread about that swap.
