Any transmission experts in the house

[durty harry]

After getting the motor swap and rear diff swap done I was getting excited about driving the 82 again but my excitement was cut short .
I installed a 383 shortblock using the same top end , vortec head intake , carb and cam as with the 355and i, swapped the old 10 bolt pegleg with 237s for 12 bolt and yukon posi and a set of 373 gear but the 700r dosnt like something , It shifts 123 before I reach 20 mph and the overdive is non existent , I notice when in let my foot off the gas it just coasts rpms go to idle and when I pull the shifter from overdrive to 3rd I can feel it shift down the rpms go up . \
Driving at 70 mph the engine is turning 3100rpms and I can pull the shifter from OD and nothing .
Yes the TV cable is adjusted correctly and still has 12 volts going to the lock-up
The trans wasnt touched during the swap , shifted fine days before I started the swap
The fluid isnt burnt, has less than 3000 miles on it since rebuild .
Im at a loss