The motor I was fixing up didnt run in the first place so driving it home wasn't an option. I live in a small enough town that Dad just hooked a strap on and towed me home (it was about a mile round trip). If your truck currently runs and you dont have it too far apart you could definatly re-tighten the bolt into place as it is really just keeping the lower pulley on (the key on the crank keeps the pully from spinning). Just get it good and tight with a 3/8 socket and you'll have no problems getting it out with a 1/2 breaker bar once you are home.

Good luck!