Hello,
I've got a 1991 f150, 4x4, shortbed, 4.9. The truck has a small 16 gallon tank. Would a big 33 gallon bronco gas tank bolt right in if I got rid of the spare tire? Thanks, JT

 

It will work, I just sold a parts truck that had one. The PO told me it was a direct swap. Make sure you get the skid plate from the Bronco, it holds the tank up.

 

You have to make support for back of tank as tank is narrower front to back . But some angle to go between frame rails bolt in and a bronco Tank ,bronco pump, bronco straps (upper and lower ,or skid plate ) I have bronco one in my old truck I need to swap to new 94. Good luck