Call Mike Ridings, you can PM him on this site at Ridings Automatics. He's great with those transmissions.
Detroit Gearbox did my 4L80E in my tow truck......Shifts better than new! p/m Rich (Detroitgearbox) he'll take care of you.
I know he's out in Warren but it's worth the drive.
Trans authority @ cooley and hospital has a good reputation. a buddy of mine has been there a few times as well as Twighlighblu92.
really? never dealt with him personally.I have nothing but bad things to say about that shop