Somewhere online I found a list of all the T-5's by serial number that showed the different gear ratios.
Basically, the T-5 came in lots of different vehicles- Ford's Chevys and others...
There are two types of T-5, the world class and non-world class. The world class has better bearings and clutch type syncros. The non-world class is a great tranny with brass syncros and old style bearings. Trucks/vans all came with the gear box in the front.
The differences between the different model T-5s comes down to gear ratios. The camaros etc... had a lower first gear and closer ratios between the gears. The truck/van T-5's had a higher gear ratio in first and perhaps a broader difference in ratios between gears, for obvious reasons (ie getting moving with a heavy load is easier with a higher gear ratio, though it is slower).
The main box/case of the T-5's are all the same but the removable/exchangable tail shaft comes with the gear shifter box in the front, near the main box, or in the rear, at the end of the tail shaft. The best one for the truck, if you are going to keep your bench seat, is the one with the gear box at the front which makes the shifter come through the floor about 6 inches closer to the seat from the original location. Those came in trucks/vans. The ones with the box in the rear came in camaros etc...
Another difference to keep an eye on is whether the tranny is set up for a mechanical spedometer or electronic speedometer. If you want to keep your original guages, you need a mechanical speedo set up or plan on spending $$ to convert the electronic to mechanical.
Another difference is the amount of torque the tranny is designed to sustain. Obviously the T-5's built for v-8s can take more than those for the L-4s. The popular ones for this truck are behind at least a v-6.
The chevy t-5 bolts right up to the original bellhousing from the truck if you just make the bolt holes a bit bigger. The input shaft is the same length within a 1/2 inch, so you might have to file/grind/cut a bit of the tip to make it shorter, no big deal. The input shaft housing may be about 1 inch too long, again no big deal to cut it down.
The last thing is the number of splines on the input shaft on the T-5 is different from the original tranny. So, you'll need the right diameter clutch disc to use it. The tranny I got had the right diameter clutch disc so I used it.
All the t-5's have a model number that begins with 1352 and is followed by a few numbers that indicate which factory configuration of gears it came with. For example, 1352-15 is an early on from a firebird. The one I used was 1352-145 from a 1985 s-10, which has both a nice first gear ratio and a fairly low overdrive.
Some people get a world class tranny and non-world class tranny with the gear box in the front of the tail shaft to put onto the world-class tranny. Other's go to a transmission house and have one built with the gear ratios they want.
Best of luck!
