Andy, your brakes might just need adjusting, or you might have some worn parts in the front end.
To check for worn parts, jack up and properly support the front end, then push and pull on the top of the tires, you can get an idea of how worn your kingpins are. For the rest of the steering, with the truck on the ground, lie underneath, and watch the draglink and tierods, as a helper "saws" back and forth on the steering wheel. Wit the truck up on the jack stands, you might want to check your front wheel bearings, and adjust the brakes all the way around the truck, this is covered in the shop manual. Sometimes if one of the brakes strikes the drum first, you can get a jerk for a second until the others touch. Worn kingpins can have this affect too. Checking out the brakes and adjusting them is never time wasted, although it isn't as fun as working on the engine!
As for the hot start troubles, have you rebuilt/cleaned the carb and fuel pump/filter? This might also sound stupid, but is your gas-cap vent working? Is your fuel line run in the stock location? Is your battery fully charged? By working methodically, you'll get it solved. If you can restore tractors, you can work on the truck for sure!
