[CompClassics]

ALF,

It looks like you have one of two problems going on, either your transmission is moved to far towards the left side of the vehicle or your floor pan is to wide (fabricated incorrectly). I can not tell by the photos if your transmission and mount are secured to the crossmember, if it is then your floor pan has been fabricated incorrectly. I doubt that the transmission mounting bracket is installed on the chassis incorrectly, check to see that the right side of the tail shaft housing is nearly touching the parking brake mounting bracket. It also appears that you are using the correct tail housing.
Tail housings can have different mounting positions for the shifter selector box depending on the original application. The correct tail shaft housing for either the T10 or the Top Loader in a 289 Cobra chassis is the same one that was used in a 1963/64 Galaxie both transmissions were available in the Galaxie during this timeframe, the shifter selector box mounting position and overall tail shaft length are the same. You can actually use the same shifter selector box on either transmission, the Top Loader selector box is a little more robust as the selector box pivot shaft is larger in diameter (stronger). The transmission main case is irrelevant on the Top Loader or the T10 as it can be either a wide mounting pattern or a narrow mounting pattern it does not matter as it does not affect the shifter position or transmission overall length.