[Terry M. Hunt]

Searched the forums for info on exactly what this vacuum tee is supposed to look like. Found a pic on page 319 of Restoration Guide(the first edition) that matches the descriptions,etc. found in previous posts. Some had indicated in previous posts that this piece was available as a reproduction part, but I don't find it in any of my GTO supplier catalogs. (Some of my catalogs probably aren't latest editions.) Poked around on PY on line catalog also, but did not find it there. Anybody know if there is a reproduction of this available before I post a Wanted ad for it? My car is a 4 speed/non AC car, so I also need the Threaded Sleeve style plug in place of the Threaded Sleeve nut (that would secure the A/C vacuum pipe or modulator line for auto trans.) I'm guessing this plug is the same one sold to plug the 90 degree fitting at base of front carb on cars w/o power brakes. Can anybody confirm that?

[Dick Boneske]

I will send you a picture of the '65 Tripower vacuum fitting for the front carb base tomorrow. It is a Tee that connects power brake vacuum on the driver's side and vacuum carb linkage vacuum on the passenger side. Non power brake cars have the brass plug you described and '65 4 speed cars have a rubber nipple over the other side of the Tee.

You are right that there are no repros of this fitting--at least I've never seen one. This fitting was used on ALL '59-'64 Tripower setups and on the '65/'66 setups with automatic transmissions (vacuum linkage). There was no vacuum line to the '65/'66 automatic trans.

This fitting is not hard to find. I have several.

[John V.]

Dick, I think Terry is asking about the Center Carb Tee.

Here it is from a mag article.

Note, the '64/'65 GTO never used the connection on the RH side of this Tee.

The GTO always had a Threaded Sleeve Plug in the RH outlet. I have found Threaded Sleeve type fitting suppliers offering the same TS Nuts & Nut Sleeves that were used, in most cases still listed under the same p/ns used in the '60s.

But I have never found original type TS Plugs, maybe just haven't looked hard enough.

The RH outlet was only used for the big Cars (with or without A/C), it supplied Vac for the Vac operated Heater Control. The Tempest Heater did not use Vac operation.

The LH outlet normally supplied Vac thru a fitting to the Dist Vac Advance unit, by way of a Vac Hose.

Some big Cars used ported Vac Advance from the RH side of the Center Carb Bowl. In those cases, the LH outlet of the Tee was plugged.

All GTOs used the manifold Vac Advance off the LH outlet of the Center Carb Tee.

As to the Front Carb fittings, Dick, if I understand what you are saying about the Auto Trans applications, I don't agree.

First, Terry, you would always need the Plug for any GTO for the RH outlet of the Center Carb Tee as noted above. Vac for the Super Turbine Auto Trans was not picked up from the Center Carb Tee and the A body did not require a Vac connection for the Heater or the A/C.

The big Car did not require a Vac source for the Auto Trans in '64.

But the big Cars did require a Vac Source for '65 when they went to the TH400.

The attached MPC Illustration shows how this was done. Although it is not labeled, the arrangement illustrated in the upper right is the Tri-Power arrangement.

The Plug Item 16 was deleted when the car was equipped with Auto Trans and Power Brakes and the Vac Pipe for the Power Brakes connected where the Plug is shown.

I believe the Power Brake Vac Pipe was just a little bit different for the Auto Trans cars vs. Man Trans.

Unfortunately, there is no similar Illustration specific to the GTO with Auto Trans.

It is my view that the '65 GTO with Auto Trans was set up the same as the '65 big Car with Auto Trans.

This set-up was similar to how the '64 GTO with Auto Trans was set up, except evidence suggests that the '64 Vac Extension Pipe (Item 13) had a longer extension so that it was solid (no rubber hose) between the Extension and the Front Carb rear fitting.

It is possible that the '64 solid Vac Extension Pipe was revised as a running change to the '65 more flexible arrangement sometime during the '64 Model Year.

None of that matters to you for a man trans car unless you have Power Brakes.

My speculation is that for a '64/'65 man trans GTO with PB, the Vac Extension Pipe was not used. Rather, a specific PB Vac Pipe was connected directly to the Front Carb rear fitting.

Unfortunately, I have never found enough evidence to prove the Vac connections for the PB with or without Auto Trans.

I assume without PB, the '65 man trans GTO used a Plug in the LH outlet of the Front Carb rear fitting, while the RH side has the rubber cap on the RH outlet nipple as Dick described.

Dick, my question is, why do you say, "There was no vacuum line to the '65/'66 automatic trans."?

[60sstuff]

Terry - Here are borrowed pics of the Tee with factory plug used on the back of the center carb base.

[60sstuff]

Some helpful pics for what it's worth - 65 and 66 would typically have this brass ell fitting coming off the front carb base. Factory slotted plug installed without power brakes and a power brake car would have a short steel line threaded into the ell that would meet with the steel vacuum line from the P/B booster held together with a clamped hose as seen in the old magazine pic.
I have seen another style brass ell (bigger block design) also used with a different cap plug.

[Terry M. Hunt]

Thanks for the replys. I already have the correct fitting and plug for the front carb that I got from Ames. It's that elusive center carb tee that I'm trying to dig up. I may have read through the replies too quickly, but still wondering if the steel plug with the slot in the head that Ames sells with the front carb 90 degree fitting would be the same one needed on the passenger side of the center carb tee. Appreciate the photos also, since it can get tricky trying to describe what some of these pieces look like.

[60sstuff]

Terry - I don't know what the repro suppliers offer, but the OEM slotted plugs used on the Tee fitting are much smaller than the one I show on the ell fitting above.

[Terry M. Hunt]

60's, I see that difference myself after studying the enlarged photos more closely. I would have sworn I had one of these center carb tees, but rummaged through my spare stuff and came up empty. Wonder what it would cost to have one machined out of brass. With all the many small TriPower parts and pieces being reproduced, seems odd that this one has never been made.

[John V.]

Terry, according to the MPC Tri-Power Illustration, the 3 way Front Carb Fitting used a 9/16"-20 Plug in the LH outlet when not used.

I should not have relied on memory when I made my first post.

Seems I have forgotten a few important things.

First, the '64 GTO with A/C apparently did use a vac source (I didn't go back to check what the vac was for, possibly a valve underhood). This source was taken off the RH outlet of the Center Carb Tee, same as the big car used for the Heater.

The '64 Center Carb Tee Plug was used in numerous applications at least as far back as '59 and was a 5/16"-24 Plug.

But there was an important change for '65.

The '65 Center Carb Tee was revised. It was not the same as the '63-'64 Center Carb Tee (which in turn was different from earlier Tees). The '65 Tee was p/n 9780984.

I believe the main difference (and perhaps only difference) for the '65 Tee was a change in the RH outlet dimension.

When the RH outlet was unused, the Plug used was p/n 9780983 (note the consecutive sequencing of the Tee & Plug p/ns).

This was a 3/8"-24 Plug.

60sstuff, that Front Carb el in your pix looks to be a Threaded Sleeve Elbow. They are commercially available today but may look different. Not sure if you can find one with the correct male and female sizes.

If it was used by the Factory for Man Trans applications in '65 & '66, I was not aware of it.

Like Dick, I had thought the same Front Carb fitting (special 3 way type, maybe Dick can post a pic) was used on all Front Carbs.

In '64, this was true for sure, since all factory T-Ps used the Vac Secondary linkage.

But for '65, the special 3 way fitting is listed in the MPC for both the Tempest & Pontiac T-P with Auto Trans only (they still used the Vac Secondary linkage).

No Front Carb fitting is listed for the '65-'66 T-P with Man Trans which used the Mech Linkage and had no use for Vac off the RH side of the Front Carb.

Lucky for me, if there is a "controversy" about the correct Front Carb fitting, it doesn't involve the '64!

While nothing is listed in the MPC for the '65/'66 Front Carb fitting with Man Trans, the Threaded Sleeve Elbows are listed in Gr. 8.963 in the MPC (along with Threaded Sleeve Connectors and Nuts). The illustration is pretty close to your picture.

So what is the consensus for the '65 Front Carb Fitting with Man Trans? Simple elbow or same 3 way fitting used with the Vac Secondary linkage?

[60sstuff]

Simple elbow. Another style brass ell fitting pictured below with cap plug which was removed from a front carb base on a non P/B GTO. Although it's hard to see, an Original Family Owned red 66 that belongs to a forum member has the first design ell I posted above w/slotted plug. Then the second GTO pic I saved from an ebay auction shows the second design "block" style ell with cap plug. Pictures speak a thousand words. Nothing like 45 yr. old OEM fittings!

[Terry M. Hunt]

Can anybody provide the dimensions for the '65 tee? I understand from the discussion thus far that it is shorter than the '64. I'm guessing I will need dimensions in order to insure I get the correct piece should I locate a tee for sale. If seller is not familiar with these subtle differences, I can see how I could easily wind up with the wrong piece.

[Terry M. Hunt]

Found a reproduction in the latest on line catalog from Ames under P/N N136P. No photo available yet. Ordered one today. At $36 it better be perfect.

[frankjr8]

It will be great or send it back!

[Tom Vaught]

Originally Posted by John V.

So what is the consensus for the '65 Front Carb Fitting with Man Trans? Simple elbow or same 3 way fitting used with the Vac Secondary linkage?

Most of the ones I have seen for 65-66 Manual Trans were a simple elbow (not like the
64 Tee).

Tom Vaught

[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.

[60sstuff]

[QUOTE=Dick Boneske;3993874] 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.

Dick - Great info (not rambling) and pics! This thread may be a little more than Terry asked for but that's why this forum is so valuable. Maybe 66 4 BBL cars used the hollow stud for dist. vacuum, but the 66 Tri-Powers got the dist. vacuum from a short straight brass nipple threaded into the center carb base as seen in the pics below. The hollow stud would have a factory black plastic cap. The exception would be the Cal. Smog Tri-Powers which used the steel line off the right front center carb body. I think the A/C vacuum in 66 came off the hollow stud.

[Terry M. Hunt]

Never too much information. I print all this stuff and keep it in a giant binder. Probably need to start a second one. Many thanks, Dick, for the photos and info. Put yourself down for a Honey Baked ham also.

[Dick Boneske]

Thanks, guys for the tolerance. I think 60sstuff is right. The straight nipple off the center carb base supplied distributor vacuum for '66's. The hollow stud is for A/C vacuum controls.

John V.---earlier in this thread you asked why I said no vacuum line went to the automatic trans on '64/'65/'66. Isn't this true?? The first trans I knew that used a vacuum line was the TH400 in '67.

[Carl A]

I'll send $20 to the first person who posts pictures of their stock original early 65, Tri power, P/Brakes auto trans GTO--- how does the modulator vacuum line hook up. This is what I have so where does the line go?

[John V.]

Dick, look for my email on a related matter.

The Super Turbine used a Vac Modulator. The big car trannies did not have a Vac Modulator thru '64, but they started using the TH400 in '65. The GTO of course used the Super Turbine so always needed the Vac line.

Carl, no fair, I don't have such a car!

Your pic shows the Center Carb. Dist Vac hose connects to the nipple off the LH side. The plug stays in place unless you have A/C. Not the vac source for auto trans.

Go back to post #3, download the drawing that I posted.

I am 99.9% certain that it reflects exactly how vac was routed from a GTO Tripower to the Vac Modulator.

It is picked up from the LH outlet of the 3 way fitting at the rear of the Front Carb.

You would remove Item 16 Plug to install a hard line for the PB directly to that outlet. The PB vac pipe routes along the left side valve cover, terminates somewhere toward the back and then a vac hose connects from there to the booster check valve.

Usually, you will see the PB arrangement for the Man Trans only, which was connected in a somewhat different manner and used a differed PB vac pipe as a consequence. If a reproduction is offered, I believe it is the Man Trans setup only.

The modulator vac starts at the modulator with a short piece of vac hose. Then a long hard pipe (Item 1) runs up to the RH side of the Carbs, all the way to the front of the Front Carb, then loops around and finally connects to what is called the Vac Extension Pipe Assembly (Item 13) using a Threaded Sleeve Connector (Item 12). From there, a couple bits of hose, a short piece of pipe, and a Threaded Sleeve Nut connects it to the LH outlet of the 3 way fitting at the back of the Front Carb.

Threaded Sleeve fittings were easy and cheap fittings for connecting vac pipes. Pipes were not flared. Tighten the TS fitting and the pipe was held reasonably vac tight. Theoretically, they were also easy to disassemble, but a little corrosion and in short order, they were not coming off without destroying the pipe.

The toughest pieces to track down would be Item 1 (a correctly bent Vac Pipe, IIRC, it was specific to the '65 GTO, the bends and/or length of the one used for the big car somewhat different) and Item 13 (the Extension Pipe Assembly, somewhat easier to find because it was same for big car).

As you view the drawing (which is specific to the big car), note that they show the two different routings for the Vac Pipe, the one I described for the Tripower and the other that routes differently for a non-Tripower. You have to follow it carefully to understand what is being shown.

I too would love to see a complete original setup pic just for reference. But I'm not holding my breath, I have looked before for both the '64 & '65. Yet to come across one.