I wouldn’t give more than $5,000 around here living in SE Oklahoma. But if you can find a clean donor truck for the parts mentioned at a cheap price then that could save you some money on replacing the items mentioned. But being it’s owned by a relative I wouldn’t give more than $4,500. Granted it’s a Cummins motor but from what you’re saying, that sounds like a lot of work. It all depends on how nice you want it to be. If you’re still planning on it being a work truck then have at it. If you’re wanting something really nice then I might consider going a different route. All depends on your pocket book.