Slightly off topic, but with all this talk of OD and 5th gear, I've always wondered what was the actual/technical difference between a 4spd with OD (effectively OD acts as highway gear, or additional gear) and a 5 speed transmission. I've never seen or heard anything about this being a 5 speed O/D transmission - just a 5 speed. My 97 4Runner 4 spd with o/d went through 4 gears, shifted into OD, and depending on the scenario, you could also feel the torque converter lock up. My 04 V8 runs through the 5 gears, then one can feel the converter lock up as well.
So what's the difference between a 4 speed with O/D and a 5 speed?