i have a 1978 f-150 that is at its stock position and want to put a 3 inch body lift on it. what is the largest size tire that will fit? what i want are some 33"X12.50, will there be any mods i will have to do to make them fit?

 

I had a 77 F150 with stock front end and three inch blocks under the rear springs and it had 33's.
Aaron

 

I have a 78 F-150 too. When my truck was stock it easily fit 33x12.5. You should be able to fit 35's no problem with a 3 inch body lift.