You can check out Marlin's transmission ID page:
- http://www.marlincrawler.com/htm/transmission/transmission.htm

Not sure of the model information plate on that early of a truck would have the trans. info, but worth a look:
- http://www.4crawler.com/4x4/ToyVIN.shtml

And while I wish Marlin were located in Fremont (20 min away from me), he is actually in Fresno CA (3 hr. drive).