904 Transmission issues.

You didn't do anything wrong installing it. But your trans. guy should have at a bare minimum replaced the pump gears when rebuilding it even if they looked fine. A set of gears don't cost much but sure are a bunch of work to replace as you know. For an application like yours running a stroker that plans on racing it I won't even rebuild one without installing hardened gears. Sure sorry to hear all the work your going through cause of this.