Three on the tree

Looks like dartcuda and waggin has pretty much nailed it for you Mike. There aren't any pads on the tail to mount a shifter on the transmission you have and you will have to cut the floor and find a shifter hump. Since the shifter hump has to be from a '64-'66 they can be hard to find and pricey. Probably the best bet would be Brewer's. They have an affordable hump in fiberglass. Took me 2 years to find an original one for Hester and I paid more for it than I should have. Once you have a hump, you can either get an aftermarket shifter kit for your transmission or swap in something else. If you decide to keep a 3 speed, which will allow you to keep your current bellhousing and front driveshaft yoke, you will need one from '68 to '76. They have the shifter bosses and SYNCHROS on low gear but the ratios are a little higher in 1st and 2nd gear.
Here's what I did for Hester. Went out and found a setup from a slant 6 Volare/Aspen and used an OD 4 speed. The truck/van stuff won't work.You will need the bellhousing, clutch fork, the tin covers, the transmission and shifter, and the front yoke. Bolts right in, uses the same clutch and rear mount, and the clutch linkage lines right up with the fork. You will need to swap the speedometer drive from Victoria into the 4 speed and change the front yoke on the driveshaft. You wind up with a 3 speed with the same ratios you have now with an overdrive for cruising. Win, win.