Yes I did the rebuild myself..roller locked up fine and was in good condition. I also put in the 34 element sprag. I did more testing this weekend...this occurs in all gears not just low.
I put the line lock on and rev it to 6000 and the tires never moved..then put it in 2nd..tried the same thing...no tire movement...3rd same deal.
Under a light throttle it will back up and move forward and get up to speed 60 mph...
I am thinking that its the stator in the converter...even though its a new converter