318 for 1965 Barracuda

dibbons said
If you have a Torqueflite automatic transmission, depending on the year of crankshaft and torque convertor (If they are not the same production year), sometimes a bushing/spacer should be used.

Slant 6 Torque Converter Bushing

I knew of the need for a tranny adapter bushing. The builder was suggesting the possibility of a difference in the blocks.