[Dick Boneske]

I attached some pictures below showing the center carb lever extension sold over the counter by Pontiac dealers for mechanical linkage conversion on the '64 GTO. It used the rod and tube link rod instead of the slotted rod to the rear carb. I believe it was introduced before 1964 for the big cars and was the only thing available until '65. It won't fit on a '64 center carb throttle lever unless you drill a hole where the typical protruded locator is positioned on the top of the lever. There was also a triangular-shaped center lever extension for the rod and tube linkage introduced even earlier. I have a copy of the factory blueprint dated 1961 for this earlier setup. If anyone is interested I can scan it and post it.

Both of these mechanical linkage conversions were available well before the "J" shaped extension and slotted rod like the '65 Tripowers used.

This is not intended to begin controversy over what was available and when. Several people have asked me to post pictures of the "other" style lever extension.

[War eagle]

Thanks for posting Dick. I agree that this part of a kit is prior 64, which brings up a question as to why did Dick Jesse, Wangers, not use this extension, as seen in those early GTO magazine tests and articles as to what is involved in the 'Bobcat" build from Royal Pontiac? The lever looks nothing like the one in the articles, but they most certainly used the rod and tube linkage. The extension you post really looks to be a good problem solver with that linkage available and also appears to allow the GTO cable to be attached. (????)
If anyone has one of the extensions and wishes to sell, please PM me. It might be interesting to set it up and see whot's whot.

[gto_ron]

Dick

Since you opened the door to linkage, I have a question. My center carb bottoms out the accelerator pump in the well when I floor it. This prevents the end carbs from opening up all the way. If I force it farther the accelerator pump linkage arm bends shorter and holds the throttle return off the base when I back off and the idle goes to about 1500 rpm until I re-lengthen the arm. Where should I look for the problem?

I'm using the aftermarket center carb lever because my original was damaged beyond repair.

regards

[War eagle]

Off hand it sounds like the wrong accelerator link or bend. Adjustment is made by bending the rod and following the carb kit instructions or chassis manual. Post a pic here and the carb guys will be able to see the linkage.

[Old Man Taylor]

It sounds like you are trying to open up the center carb too much. First make sure your accelerator pump is adjusted to spec. Then adjust the tang on the driver's side of the throttle shaft on the center carb so that it stops just as the butterflies are fully opened. Then adust the rod from the front to the rear carb until the end carbs are fully opened. Adjust the tangs and the rod on the passenger side as required.

The sequence of adjustments will vary depending on your specific results.

[Dick Boneske]

Ron,

As OMT and War Eagle said, either the adjustment or the components in the accelerator pump mechanism are wrong.

First, as OMT said, make sure the center carb only opens until the throttle blades are fully vertical. If not, the main throttle lever stop tap is bent or missing.

The accelerator pump rod must be bent so, when the throttle plates are closed, there is 1 1/8" between the top of the airhorn and the top of the accelerator pump rod. If that's not the problem, it's possible you have an accelerator pump that's too long and hitting the bottom of the pump well before the throttle is all the way open.

If you can take a closeup like the one in my OP, I should be able to give you better advice.

[Doug]

The first I ever heard about the factory rod-tube stuff was about a year ago. Up until then I figured that I was a pretty smart guy when I rigged up a rod-tube setup a few years ago.

If I recall correctly, my pieces/parts included linkage fittings from an older junkyard Ford truck, a piece of faucet supply line tubing and bits and pieces. The setup has about 1/2" of "overlap" of the tubing over the rod and allows for adjustment of the approximately about 1 1/2" of "slide action". Here are some pics:

[Dick Boneske]

Doug,

That center lever extension is the same one as I pictured in the OP. In my 40+ years of playing with Tripowers, I've only been able to procure the one extension I showed in the picture. Where did you get yours?

Great job on fabricating the other pieces, by the way.

[War eagle]

Dick. Back to your original post. The triangle plate you mentioned is the one I think I see in the CARS, THE AUTOMOTIVE MAGAZINE March or similar pic, april SPEED AND CUSTOM. One thing that is addressed with the triangle plate as well as the extension you have, is the alignment or attempt to align the return spring. With a 64 and using the J strap from the 65, some alignment problems exist. I hope someone can post one of the two magazine articles I listed. The Wanger`s car in the article, shows the spring attached to the bottom of the triangle plate, via a 1/2 in bolt made from a length of hex shaft with a light groove to retain the spring hook. This extended end moves the groove more in line with the throttle brkt spring hook holes. Although that is the way it was, I don`t believe that continued throttle cycling of the spring hook over the large 1/2 in groove would be in anyone`s interest. Maybe the engineering of this wear spot is the same guy that did the first design Tempest lower front door hinges.

[Doug]

Dick,

I've bought/sold/used 6 or 7 tripower units (65's-66's) over the last 20 years plus I have picked up several junkyard 2-bbl Rochester carbs but none of them were tripower units as far as I know. I assume the piece in question was already on the carb when I got it. Is that piece a repro piece now?

[War eagle]

Dick PM sent

[Dick Boneske]

No, no one repros that lever extension.

I have repro'd the triangle-shaped one for many years. It works with either the rod & tube or slotted rod link.

[John V.]

Dick, here's a pic I've "collected".

I've "studied" the '64 Mechanical Linkage parts as well as the Kits.

I'm not aware that there was any usage for this lever prior to '64.

PMD always had made Mech Linkage Kits available for the big car Tri-Powers prior to '64.

The Kit for the GTO however was a bit of a late intro based on the p/ns issued for them and info contained in the Sales Brochure. The '64 Kits were apparently available by the time the Revised GTO Sales Brochure was printed in April '64 (that version also mentioned the close ratio trans availability for the 1st time).

I can't recall off-hand if the '64 big car Kit used the same p/n lever as the GTO Kit, would have to check that.

Tom Vaught has a complete kit set-up on his, it was already installed when he acquired the car as the 1st retail owner, it was first used as a Co. Car prior to his acquisition.

[Dick Boneske]

Yours is the same extension bracket as mine. Do you think this is THE PIECE that your dealer would have sold you if you complained about the vacuum Tripower linkage? I remember that most of us went to Hot Rod Shops and bought the infamous "Ansen Ball Bearing Linkage Kit." Most of us didn't know we could get help from a Pontiac dealer with items like this. Most of them though we were nuts for buying a Tripower GTO to begin with.

You may have noticed the bottom hole & 1/4" bolt fits fine with existing hole in the throttle lever. There is no hole in the '64 throttle lever that lines up with a hole on the extension to secure the top. It does line up with the extruded (raised) circle on top of the throttle lever. If this is drilled to accept a 1/4" bolt, the bracket can be attached to a '64 throttle lever.

It is not typical, however, for a factory "kit" to require any machining--even as basic as drilling. If you recall, the rear carb throttle arm was supplied swedged to the throttle shaft--not secured by the 8-32 screw we've been using.

Bottom line--How do you think the extension bracket was secured to the throttle lever?

[60sstuff]

A 64 with this mechanical linkage

[Dick Boneske]

Thanks for the picture. I can't tell how the top of the extension is secured onto the throttle lever. Can you see it on the original photo?

[John V.]

Dick, yes, this is the '64 Mechanical Linkage Package. It included several parts.

I am not an expert on this but have studied the parts and p/ns a bit.

You mentioned the "triangular" piece.

Early mag articles showed this set-up. I believe either the '64 Kits were not yet released (most likely, IMO), or Dealers like Royal were used to working with the older Kits and simply installed them on the test cars rather than acquire the "correct" Dealer Accessory Package.

The GTO Package was p/n 9777060, the big car Package was p/n 9777061.

Presumably all of the parts to make the conversion were contained in each kit Package.

This included the Center Carb Lever Extension, for the GTO p/n 9777063 and for the big car p/n 9777064.

Since the big car used a different style lever extension, I will continue for the GTO only.

There was the Throttle Control Cable Mounting Bracket p/n 9777062 which was specific to the '64 GTO Mechanical Linkage kit Package.

As to your question about securing this throttle lever extension to the Center Carb Throttle Lever itself, I'm not real sure how it was to be done. I agree with what you described for the lower attachment, the reglar 1/4"-28x1/2" hex bolt and nut secured it, same as for the factory lever extension.

At the top, a stud may have been used. This may be the stud described in the MPC (Gr. 3.425) as the '64 Throttle Control Cable To Carb. Lever w/ Mechanical Linkage, p/n 9777067. Based on the p/n, it was undoubtedly part of the kit Package.

But nothing I've seen indicates that there was any upper attachment of the Lever Extension to the Throttle Lever. The pic I posted shows the raised circle on the Lever still intact.

How was the regular T-P Lever Extension attached, were there 2 attachment points on it?

The last identified component is the Throttle Shaft & Lever p/n 9777065 for the Rear Carb. It is listed in Gr. 3.463. I do not remember why this part needed to be replaced to facilitate the Mech Linkage, I think it was to get the specific Lever, swedged to it. I assume the Throttle Shaft Return Springs were also changed for the heavier ones but that would not have required the removal of the Throttle Shaft. IIRC, Tom Vaught's Rear Carb features this Throttle Shaft and the heavier springs.

The p/ns assigned to the kit Packages and the associated parts (977706*) is why I believe these parts were released relatively late in the year. Chronologically, they were issued after certain other parts that did not appear until late, such as the '64 M21 trans which was p/n 9777000.

My own guess is that they were not available at the Dealerships until about April, '64. Any earlier conversions would have been aftermarket stuff or cobbling together from the earlier Mech Linkage Kits such as was seen in some of the mag articles about the '64 GTO.

[War eagle]

The revision of 7-1-64 grp 3.454, shows no kit but does show an extension asm for 64 GTO 9776284. I may be inclined to believe a kit was out there specific to the GTO extremely late in the year, but Royal was supplying their kit earlier. Probably the triangle adapter. John do you have a pic of Tom`s factory kit? Also why are you now on board with Dicks extension after your earlier post?

[John V.]

Not sure how early the '64 Linkage Kits got in the MPC, mine is effective Oct. 1, 1965 for the 1966 Model Year. If they were not in any of the '64 MPC revisions, perhaps they were in the Price List by p/n? I know they were still in the later ones until obsoleted around '73 or '74.

I don't think I have any pix of Tom's set-up. Not sure what he has been up to, I was hoping he would wander in here. I believe his installation is as close to what the kit was supposed to be as can be found. He should be able to answer Dick's question about the upper attachment of the Lever Extension to the Lever, if there was one.

Be careful what you call a "factory" kit. To be clear, the kit Packages were only available thru the Dealers. Tom does not know why his car was converted to Mech Linkage or by who or even when, but it rolled off the final line with the Vac Secondaries.

One of the more interesting insights Tom has revealed, his Rear Carb has the correct lever for the Mech Linkage. But he sees no evidence that the throttle shaft in his Rear Carb was ever replaced, raising the possibility that the entire Throttle Body was included in the kit Package, not just the Shaft & Lever. If so, I have never found a p/n for the Rear Carb Throttle Body Assembly for the Mechanical Linkage.

I may have not been clear in my earlier post. I have ALWAYS been on-board with the Lever Extension in Dick's set-up being the correct '64 GTO piece as found in the kit Package p/n 9777060. The pic I posted was intended to convey that his was not the only one out there. 60sstuff also posted another one.

I believe Tom has collected a couple in addition to the one that came installed on his car back in '64.

I'm hoping Tom can jump in to tell us how the Lever Extension was attached to the Lever.

Dick, I'm still wondering how the factory Lever Extension was attached to the Lever for the Vac Secondary arrangement.

One other question, I did not look closely at your pix, but are you using the '64 Throttle Rod plunger set-up or some other arrangement? I think something looked odd about it but not sure.

[pfilean]

John V. 1-4 2:27PM

The last identified component is the Throttle Shaft & Lever p/n 9777065 for the Rear Carb. It is listed in Gr. 3.463. I do not remember why this part needed to be replaced to facilitate the Mech Linkage, I think it was to get the specific Lever, swedged to it. I assume the Throttle Shaft Return Springs were also changed for the heavier ones but that would not have required the removal of the Throttle Shaft. IIRC, Tom Vaught's Rear Carb features this Throttle Shaft and the heavier springs.

John, are you saying that the mechanical linkage had the stiffer springs? I am currently running a 1964 GTO carb setup on my 61. It was originally a vacuum unit but has been converted to the slot style mechanical. I think the springs are too strong and there were no springs included in the conversion so I think it is original vacuum springs. I thought maybe the vacuum setup had stronger springs to force against the vacuum in the diaphragm for decelleration. I think I have heard the many people had concerns about the end carbs not shutting down quick enough on braking and so made the conversion to mechanical.

Also remember that the 64 GTO rear carb had a lever on the drivers side with a hole for only the accelerator pump rod. The vacuum diaphragm hooked to the passenger side of the rear carb in one hole on the lever on that side and a second hole in the lever operated the front carb. So to convert from vacuum to mechanical some provision was made to convert the drivers side lever to accept the mechanical hookup. Whether that was a replacement lever (as is done on the current aftermarket conversions) a new shaft with the lever already swedged on, or a whole throttle base I don't know.