I just bought mine after X-mas and I love it mine is a 99.5 see if you can find the build date they made some benifical changes but the early ones are still very good trucks . Are you saying that it has three hundred fifty thousand miles on it if so how long has your dad owned it.
I agree with cookie so long as it has been taken care of you should be fine .There are guys in FTE with 500,000 and 750,000 miles and are doing fine. I know my dad wouldn't sell me a piece of junk I would hope yours wouldn't either.
Cookie finally got a good steak, see he's much better now.