Here is some information from Trifive.com . The info is a little old from an old manual but still good information on powerglides. It may apply to your situation . I am sure you are running a later glide but the troubleshooting may apply
https://app.box.com/shared/dmcutnumq0Not sure what is in your neighborhood for old car clubs. If you can find one they often have good contacts for reputable shops from paint to mechanical . Good luck.
