Welcome to the site! The 5L 5speed swap is easy, but to do it the way I did you will need a welder or someone to weld for you, becuase I cut the trans cross member in three pieces, and moved the center section back so the tranny could bolt up, and then I tacked it together. Then I welded it all up. I used the cross member off of the T-Bird that I pulled my engine from, I just cut down the ends where it fits into the mounts. The double hump cross member seems to be twice as wide.
I saw somewhere else someone bolted the cross member to the back of the mounts so it was only in on one side, and its possible to cut the tranny mounts out of a mustang and weld them on to your fairmont, which I did on my other car, and was a big pain in the ass.
If you dont have a welder it could be more of a pain, but maybe someone else has done it an easier way. I didnt have a welder with my first car, I just borrowed a friends, but now I use one I bought for $200 at a store here on sale, its made in china and can be a pain in the ass, but it works..