I have an 83 Fox Body with a 5.0 4v and a 5 speed manual tranny. I want to turn it into a pro street car. I wanna start with the rear end and work my way forward. Right now it has the 4 lug shafts and I was curious on what I could do to swap them to 5 lugs or if I need to swap axles all together.

 

There are several 5 lug conversion articles if you do some searching, even think there's one in the tech articles on the main 5.0 page

 

the 83 came stock with a 7.5" rear so unless thats already swapped out then i would just try to find a 8.8" rear out of an sn95. that way you get 5 lug + disc brakes.