Not that it makes any difference, but I don't remember ever seeing a 90-94 with an analog dash. Otherwise, I'd have bought it.
Your TV bushing isn't bad, otherwise you'd have spit that tranny out a long time ago. It would also be shifting into each gear at the earliest possible time (like 9mph, 18mph, etc) and it would slip like a mofo in OD.
As far as top speed, that '90 should go all the way to 140 unless there is some strange limiter in there. I knew a couple guys who did that in their 80's cars. Never tried it in my old '89, it just was too dangerous for me.
Here's how you'll get a ton of power out of that '90. . .
Make the HO conversion from an 89-93 mustang or Mark VII, but instead of rewiring the injector harness to make the injection order correct (which is essential if you keep the stock computer, but doesn't work well because the computer is confused about which cylinders are putting out what O2 levels) install the 89-93 mustang computer. That computer will also adapt to any changes you make to the engine later, which is a must.
Next, throw on an aftermarket intake manifold, heads and headers, and put an X pipe with high flow cats on your exhaust. if you choose the right parts you will be comfortably above 300 horsepower. Leave the stock cam so the engine still has good manners at idle and still has that oh-so-sweet 5.OH sound! I love that sound so much. . . . .
Anyway. . . thats what I'd do. You won't be ripping that quarter mile to shreds, but you will be cruising around town in a TC that runs WAY faster than it was designed to and will turn a lot of heads.
Heck, an HO swap alone will have people asking you "hey, is that a 'hot rod' Lincoln?" I know mine did!
Happy Cruising!