Differential question
 

Will a 1990 N/A FC Differential guts fit inside a 3rd Gen Differential?

Im not an expert but i belive its an open diff and has 7'' ring gear. They may have a posi unit but i dont think it works. I would tell everyone why you need to do a diff change. A 87/88 t11 clutch diff fits or replace it with the stock torsen.

Here's 2 rough pics of my diff, there's some teeth grinded down which caused slipping and wheel hops, so that's why I'm changing out.

I know the TII stuff works but I don't have one available and a friend of mine said he's got a 90 N/A one but I'm not sure if it will work or not.

The TII not liquid diff will fit in a FD fine and it can handle more power than the Torsen. Ask the LS1 conversion people as that is what many do.

I dont think it will do what you want. There is usually a torsen for sale in the parts section. And there is sometimes t11 diffs on there as well. Put WTB and ask! Im putting down 1.522 60 ft times with the t11 diff.