the place to start is getting it 100% mechanically, complete driveline freshening, including maybe an engine rebuild [requiring machine shop work], total brake job, possibly requiring lots of new bits from the lines to the cylinders and maybe even drums, which could be hard to find for a 3/4T
I dont want to put more into it than I will be able to eventually sell it for
better put the for sale sign on it right now, you're looking at a fair bundle of money for parts and material without fancy eye candy, and 3/4T trucks rarely sell for as much as 1/2T's
Bill