I have a '65 F100 with a 352 and I'm looking for an overdrive tranny. What will work in this truck?

 

RUG/T170 top-loader.

 

What bell-housing and transmission do you currently have and how much money do you want to spend? If you are willing to change bell-housings and drive-shafts, there are a lot of combinations. I have owned a '65 F-100 and it had a T-98 four-speed, so I am quite familiar with your rig. Some of the old combinations possible would be either the T-86 (light-duty) or T-85 (heavy-duty) transmissions -- these both were non-synchro low gear. The older ones were made in greater numbers and are still in some junk-yards. The top-loader overdrive will have synchronized low and would be closest to stock, but would be more expensive. There are many (expensive) options if you want to go new, including the Gear Vendors and other add-on overdrives.

The rear-axle ratio of my pickup like yours was 3.70:1 which worked well for towing a 7,000-pound tandem-axle trailer, I would have gone with a 3.00:1 ratio with the four-speed if I was not towing and wanted a better road gear. Doing this could be cheap as all you would have to do is pull the third member out of a pickup or big passenger car that had a 9" Ford rear axle and an automatic transmission.

I ran a '65 Merc with this combination for many, many miles. The 390 pulled from a stop in second gear with no problems and there was always "grannie" if one was on a hill. Later on I spliced a T-85 (4-planetary gear) overdrive onto the T-98. (If anyone is interested, I'll start a new thread about it.)

Archie (currently driving a '68 F-350 with a New Process 540 five-speed)