to answer the original question from Ash,
AA Gears & Shafts did a great job on the T-5 for my Tiger
I wanted a real overdrive, not a 5th gear. My thinking was that the speed I'd run out of revs in 4th and needed a 5th would be over 100mph. That does not happen very often in my driving. However a freeway cruise at 70 or so happens all the time.
When Ford introduced the T-5 to the world in the Mustang II with the 302, their engineers inchose a .625 ratio for the Mustang II.) So my plan was to mate an early Ford T-5 main case (including output shaft) with the Chevy S-10 tail housing. AA did most of the work. (I did the speedo gear using an aluminum shim.)
1402 E Washington Blvd, Los Angeles, CA 90021
(213) 748-2194
The result is a joy to drive. We've done thousands and thousands of open road miles with it including cross country trips. Sound level and mileage are great. I'd never switch.
As to the speedo gear. I made an aluminum spacer with a slit, got it over the shaft and both pressed and epoxied it into place. However while I could have used a traditional speedo gear I chose to use a OEM reluctor. Confirming what Sean posted, GM used the T-5 into the eighties which spanned the change from geared speedometers into the electronic era. They made an OEM electronic sensor that plugged right into the T-5's speedo cable hole. Since I already owned a Tigerized electronic speedo (Tiger face on a Porsche instrument) I chose that route because of lazyness - running a wire is easier than trying to have a custom speedo cable made. Today's GPS units are easier still. I think guys in the UK are now putting Tiger faces on GPS units. I imagine there are other sources as well.
If you decide to fool with the reluctors I remember that Standard instruments sold both the reluctor and the pickup. However they had weird names. I can't remember what they were. Maybe the sensor's name involved cruise control??? I don't know.
good luck.
Buck