What other cars share the same rack as a 5.0??

You'll have to look and make sure that it's the same part you have before buying it but here's some fox body cars that may have the same power steering rack as your car:
78-83 Ford Fairmont, 78-83 Mercury Zephyr, 79-01 Ford Mustang, 79-86 Mercury Capri, 80-88 Ford Thunderbird, 80-88 Mercury Cougar, 81-82 Ford Granada, 83-86 Ford LTD, 83-86 Mercury Marquis, 81-87 Lincoln Continental, and the 84-93 Lincoln Mark VII.
It's likely the newer cars will have the high ratio steering rack that you have, but i'm not sure if that makes a difference in the fitting, they may all have the same fitting. Good luck!

------------------
'84 Mustang 5.0 LX
My car