Kickdown issue

My Dad bought a 67 Hemi Charger in the fall of 70. Automatic trans. We found out pretty quickly that above 30 miles an hour it would not downshift into low no matter what - throttle floored in Drive, or manually move the shifter to low, etc. Had a 5,000 rpm governor, and would full throttle upshift out of first and second at that rpm, but no kickdown into low above 30 mph. Fixed that with a B&M Transpack which made it an automatic/manual valve body. Now, with a manual downshift, you could get it into low gear at any speed. Can't remember about the automatic kickdown in drive after the valve body modification.

Much later, had a 68 Torqueflite in another car, and it had the same non-kickdown into low above 30 mph.

Not sure how many years this was the case, but it was 67 and 68 at least. Other years, the kick down into low was not so limited. So your trans may not kick down into low at 30 mph even if you kickdown is working as it should be and even if you have a high rpm governor.