Used Langford's here in Sugarland. Good people, local shop and did a great job.
Initial issue was caused the the nut on the output shaft backing off some. Hence the reason it was slipping out of gear in 5th when hit a bump.
New kit installed (no major damage on the gears). New heavy duty billet torque converter and also had an issue with the yokes in the transfer case and wear on the main shaft inlet of the case. New front case installed. Probably caused by slack as well.
All for $3200. Not bad considering what they did for me. Re-learn was a little over two hours. Never noticed much of anything driving it during re-learn. I do seem to notice the the extra umph of the heavy duty converter.
Check your output shaft nut - this loosening has happened to others.
He did say the tranny was a beast. Said it makes the 4L80 E look small.
Happy with service and back on the road........a little stronger than before
I did nothing to kill it and it wasn't really dead, not limped. Just a loose nut basically, which caused quite a few problems.