8 cyl swap using 1991 tbird sport as donor

pretty much no, no and no.

the tbird isn't a fox platform car after 1988...so nothing on there like fuel lines or electronics etc are a bolt on.

the 5.0 will go in, but is it an HO or a non HO 5.0?? If it's a non HO engine, don't waste your time.

what kind of trans is it? an aod or an aode??

just be careful, there may not be enough useful parts on that car to warrant buying it. You can get a healthy used 5.0 engine for well under $500

T-Bird Motor swap

I just got thru putting a 1993 t-bird 5.0 H.O. motor into a 1992 Mustang GT. The 1992 Mustang was a theft recovery where the heads and valve train were stolen. I was uncertain about the bottom end of the Mustang motor so I decided to used the T-bird engine.
The arrangement of the motor options are all in different locations. Meaning the PS pump,AC Compressor, Smog Pump, and Altenator will have no compatibility with the Fox body. The rotation of the water pump is different meaning new bastard hoses would be needed or. I used the timing chain cover(water pump) and above options along with the Mustang mounting brackets to make everything compatable.
The length of the options on the front of the T-bird motor would put the fan/blades of the T-bird motor into the radiator of the Mustang. Even the fuel lines(fuel rails) are routed different on the T-bird.
My suggestion is to find a Mustang engine for the Mustang unless you are interested in the long block (only) of the T-bird. Even the TFI connections on the distributor are different between Mustang and T-bird.
The front suspension is totally different between the two.