I am in the planning process of installing a Tremec TKO 500 5 speed transmission in a 1966 F-100. The truck was originally equipped with a three speed manual transmission. Installation of the Tremec would benefit from a little more tunnel height. I assume one could cut out the pattern in the tunnel shown above and install a transmission cover from a 4 speed or C-6 truck. Does anyone know the year range that would work for this modification? Would anything through 1979 have the same shape? It would be helpful when searching salvage yards. Thanks for any knowledge or suggestions.

 

Yes the transmission cover is the same for years 65-79.

 

Excellent !!!!
Thank you for the information - that makes salvage yard hunt much, much easier.