I was reading recently about someone using a saginaw four speed and installing the overdrive rear section off a Saginaw 3 speed/overdrive on it. Looks to be a bolt together install. Gives you a car four speed with a pretty healthy overdrive ratio. (a choice of 10 possible gear combinations!)HMMmmm!
I'd go with the T-5 conversion though. It isn't that spendy,and with all these guys to coach you,it'll be an easy install,and you'll really like the results.They shift so much smoother!!
Speed