Curious what a rebuild quote is in your area. When I lived in Richmond, shops wanted 5k to rebuild a ZF4HP22. Funny now I asked my local shop here in Asheville and they said a rebuild was 3k from their source. I felt at 5k I was getting ripped the F off.
IF I ever have to go through a auto ZF rebuild or replace again I'll order an Ashcroft and have it installed.