Will a windshield off of a 1990 f150 fit on my 85 f150? Is there a difference, I know the cabs are similar but can the windshield be swapped?

 

Yes, it can be swapped. HOWEVER, it may cause you a problem since they moved the VIN between those years and the later windshield has the clear spot in a different place than the windshields for the 80-86 trucks. I had a new windshield put in an '82 and they used a later model windshield. No problem - until I sold the truck and the DMV couldn't see the VIN.