I have a RUG M3 wide ratio from a 1969 Mustang/Cougar 390 that I need to go through. Casting date on the C8 main case is 02/06/1969. I've looked on David Kee's site and have the book he sells. The question is, would this transmission have type 3 or type 4 detents and springs? Second question, are the 1 and 2, and 3 and 4 shift rails the same or slightly different? The problem I'm trying to fix is, it really doesn't want up shift into 3rd gear but will. But it will not downshift from 3rd into 2nd gear. Any input will be appreciated. Chuck