The problem with truck transmissions is that 1st gear is often very low for pulling
heavy trailers. It will have tons of torque but wind the rpms up way too quickly to be usefull for a light car.
Better to look for a Tremec TKO (old model # was 3550) or late model T-5 that was made for 1990's 5.0L v8 Mustang. Not sure if the t-5 in the 4.6L will work, it may with a different bell housing. Don't use a T-5 out of a 4 or 6 cylinder. I have seen rebuilt T-5s for around $900 searching on the dot.coms.

 

Thanks for the info. I'll look around and see what I can find.