66 dart slant 6 to 360
New converter that's either balanced for a 360 or with the appropriate B&M flexplate. The current converter also has a smaller snout and spline count that's not compatible with later transmissions.
I keep forgetting what year torqueflite converter snouts and input spline counts "normalized" (1967?). Make sure you don't have a later lock-up trans/converter because they changed the spline counts again (around '78-'80).
New converter that's either balanced for a 360 or with the appropriate B&M flexplate. The current converter also has a smaller snout and spline count that's not compatible with later transmissions.
I keep forgetting what year torqueflite converter snouts and input spline counts "normalized" (1967?). Make sure you don't have a later lock-up trans/converter because they changed the spline counts again (around '78-'80).