[Dick Boneske]

All the '64's used the tee in the front carb, as they all had vacuum linkage (some claim there were some mechanical linkage '64's, but I've never seen one). The '65/'66 manual trans (mechanical linkage) setup I've seen had the cast brass elbow in the front carb base. If no power brakes, there was a slotted steel pipe fitting acting as a plug in the elbow. Every '65/'66 automatic trans setup I've seen uses the brass tee with the power brake line plugged if no power brakes and vacuum for the throttle linkage taken off the other side of the tee.

I've attached a picture showing all the varieties of Tripower base fittings I have. The shorter tee for the center carb (distributor vaccum and heater-A/C vacuum) is next to the longer tee. The round portion with the 1/8" pipe threads is 1" long. The round portion of the longer tee is 1 11/16" long. The longer tee was used on all '64 and earlier setups I've seen. This long tee makes it awkward to attach the vacuum lines as the tee is nearly against the rear carb. The shorter tee is used on '65 setups, but '66's, I believe, used only a straight hose nipple in the base of the center carb for heater-A/C vacuum. Distributor vacuum is taken off the hollow carb stud in '66.

The odd tee is from a '64 GTO AFB. Note it uses the same slotted steel fitting to block the non-power brake port.

John V. is right about the plug for the center carb vacuum tee. There are two sizes, 3/8" and 5/16". I didn't have time tonight to sort out which is which, but believe the '64 and earlier used the smaller plug--'65 used the larger one.

Sorry for the rambling, but I've tried to provide what you're looking for.