Probably not. I wouldn't drive it too much, though. The transmission must be removed to change it. There will be a lot more labor than parts. I've done this several times just by jacking up the truck a bit and lying on my back. You'll need to be fit, though. The transmission isn't light, but there are many which are heavier. You need to be able to lay it up on your chest and then sort of bench press it up into place. Depending on how much work your dad did in the 80s, it might be a good idea to remove the pressure plate and clutch plate and at least see how those look and how the flywheel looks also.

~ Jon
1952 1/2 ton with 1959 235 | T5 with 3.07 rear end