Tranny Shift Problem

[Lourdalfe]

HI everyone I finally got to drive my 65 it's basically a 87 mustang in a 65 body problem I'm having is after the tranny has sat for like 7 years it won't shift from second to third or od no matter how fast I go or how long I drive it just won't go past second I've checked and cleaned the gov and it was fine it shift great to second from first goes in the forward and rear gear right away and tv cable is adjusted per YouTube videos question is could there by a stuck valve or is the tranny shop right and the tranny needs rebuilt

 

[mikestang63]

did you change the fluid and filter
chances are the rubber O rings or the bands are bad from sitting

 

[Lourdalfe]

Yes but the fluid looked great and no 6debris in the pan at all