those 305's won't fit properly with a 2" lift...what is the backspace on the rim?
If you buy the blocks (only get steel), they should come with the ubolts - total cost will be like $65.
Personally, I would get a lift for the truck if you want to run 305's. Cranking to fit those big wheels is going to be dangerous and eventually your CV's will fail.
Extreme A/T are really nice tires and cost a ton for 305's...I would definitely look into the proper lift and stay away from cranking your t-bars. Also, with tires that heavy, you will be wearing out your front end faster than stock tires, so definitely stay on top of maintenance.