No 2nd gear...

million dollar question... what’s wrong?

Equipment:
727 trans
RMVB
alto red clutches
2800 stall
<5000 miles on trans
Built about 6 years ago

Issue:
Took a 40 mile drive in 98* weather. Next day it wouldn’t shift into 2nd gear. Feels like it stays in 1st. There’s no problem shifting into 3rd. I did notice that the shift into 3rd felt a lot smoother than normal (use to be crisp and firm). Trans fluid smells pretty burnt.

Background info:
727 was behind a 416 stroker for roughly 5 years. I swapped in a mild 360 in November and have been driving it ever since.

Any ideas?