64 727 Questions

I’ve got a 64 Dart 270 with a 225 slant six and a 727, with the push buttons.

I mostly drive it around town but occasionally drive it on the highway, with increasing frequency. Occasionally, especially at first, I’ll have a slight burning smell for a few seconds after getting off the highway.

I have plenty of transmission fluid, and I did an engine oil and filter change about a month and a half ago, and still have plenty of oil.

Any thoughts?