Since it is a stick (manual) trans, just check the gear oil and change if it has soured or full of water. Make sure all the linkages are free, hit them with some penetrating oil (wd-40). Pressure plate and flywheel will rust up good if it has sat for long period of time, not much you can do there except replace clutch , pressure plate, throw-out bearing and have flywheel cut. Don't oil them! Those old stick are pretty durable, not like the garbage made today. I do know the cabs also like to rot out in them, also mounts as well. Nice looking truck, all it needs is a big block, with muncie rock crusher and nice posi, and you should be able to get around just fine.