As Charlie asks, what's the use for the truck. T-5's have some major advantages, like 5 speeds and a synchro first gear. As much as I like a T-85 O/D, the combination of traffic and hills meant that for every second shift to 2nd gear, I was going to get to double clutch down the 1st.
My roadster has a TKO 5 speed, on a truck bell, modified by J Mummert.
Look carefully at the T-5. There are many variations, and some won't handle the torque of a Y. Others have an imput shaft issue. If you can't find that here, run a search over at the HAMB.
John's site on the modified bellhousings.
http://www.ford-y-block.com/t5in-trucks.htm
miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ