[68lemans462]

I recently picked up a really nice virgin and complete tripower unit from an early 64 car. I cleaned it all up and rebuilt all the carbs. Aside from the carb kits, fuel lines, rear brass fuel fitting, and the rear vacuum actuator (which is on the way) it is 100% original.

Seller says it was removed from a 64 GP with 421 and his story seems to add up but I'm having trouble finding ANY references/diagrams, etc for this. This unit seems to have some differences from the 1964 tripowers I have been googl'ing up. So, what do I have here? Are there linkage parts missing between the center and rear carb? What else is out of order?

Intake 9775088 date J283, Carb tags 7024179 J3 22, 7024173 K3 81 (or maybe 18), third is missing but all the carbs look original/legit/matching to my untrained eye.

Once i get the rest of it sorted out I'll be offering it for sale to fund other PONTIAC stuff....

[68lemans462]

More pics

[Dick Boneske]

Yes, this is a '64 Tri-Power off a big Pontiac as evidenced by the very rare waterneck and two long ball studs on the center carb. The large heater shutoff valve on the heater hose nipple should be removed. Pontiac did not use these.

All the vacuum linkage components are there except for the two steel lines for the rear vacuum diaphragm and the one from the vacuum switch to the thermostatic vacuum control valve. The front to center fuel line is bent and installed improperly, but could likely be saved. The vacuum TEE on the center carb base is 180 degrees from where it should be--the small vacuum tube is for the heater controls and the other end is for distributor vacuum advance.

It would take very little in parts and labor to complete the setup, which would be ideal for someone wanting an original '64 setup with factory vacuum linkage. I would disassemble and plate all the steel rods and levers to factory colors.

I've attached a few pictures of a '64 setup I restored for a GTO that has all the vacuum linkage pieces removed and the '64 only over the counter mechanical linkage installed--9777061. There was a similar version available for the big Pontiacs.

[Kenth]

Tags for 1964 421 Tripower carbs would be #7024079 is for the rear carb, front carb should have tag #7024078. Center carb for M/T #7024075, A/T #7024074.
Your tags indicates a 389 A/T Tripower set.
Also, the rear carb should have the pump lever with an alternative hole, like your front carb has. 1963 and earlier end carbs have only one hole in the pump lever.
Front carb air horn is drilled for a bleed off tube to the vacuum switch, rear carb is not.

[68lemans462]

Originally Posted by Dick Boneske

Yes, this is a '64 Tri-Power off a big Pontiac as evidenced by the very rare waterneck and two long ball studs on the center carb. The large heater shutoff valve on the heater hose nipple should be removed. Pontiac did not use these.

All the vacuum linkage components are there except for the two steel lines for the rear vacuum diaphragm and the one from the vacuum switch to the thermostatic vacuum control valve. The front to center fuel line is bent and installed improperly, but could likely be saved. The vacuum TEE on the center carb base is 180 degrees from where it should be--the small vacuum tube is for the heater controls and the other end is for distributor vacuum advance.

It would take very little in parts and labor to complete the setup, which would be ideal for someone wanting an original '64 setup with factory vacuum linkage. I would disassemble and plate all the steel rods and levers to factory colors.

I've attached a few pictures of a '64 setup I restored for a GTO that has all the vacuum linkage pieces removed and the '64 only over the counter mechanical linkage installed--9777061. There was a similar version available for the big Pontiacs.

Dick, thanks for all your info! I added a picture with 2 tubes I didnt picture before. One comes from the bottom of the center carb (the dirty one), the other is sitting on the bench. Are these the missing tubes you speak of? Is the throttle spring bracket correct? If so, where does it go?

What are the differences between this and the "GTO" unit, if any or what makes it big car specific? Even the water neck you mentioned has part number (9775645) shows up as "GTO" in my searches. When did Pontiac transition from the vac to mechanical units?

[pfilean]

That last tube is for the ported vacuum which I believe was only for used the Roto HM in the Catalina/GP cars. Not sure how it was supposed to be bent but that looks to have been abused.

Also in the second of the original pictures I believe I see a hot idle compensator on the back of the center carb which would likely only exist on an AC car. Also shows in the second set of pictures.

The front carb, although drilled for the vacuum bleed off for the vacuum actuator system, is missing a short tube aimed to the vacuum relay on the center carb. Would have a rubber tube to the small nipple in the vacuum relay.

Last picture also shows what I think would be the tube from the thermostatic switch to the vacuum relay.

[68lemans462]

The vacuum tube routing is still a mystery to me. I can't seem to find ONE picture of this unit. Also have not had any success finding diagrams.

[pfilean]

There was also a vacuum reservoir canister on the pass side inner fender. There was a tube from the T by the thermostat over to that cannister. You have the bracket that held the large tube coming from the back of the from carb but there was also a hose clamp from that tube to bracket.

Then there was tube/hose from the vacuum relay to the actuating vacuum diaphragm on the rear carb which you don't show. I think it may have run between the center and rear carb but also may have run behind the rear carb.

Also a short hose from the missing bleed off nipple on the front carb to the small nipple on the vacuum relay.

On the thermostatic valve on the from of the manifold the nipple closest to the manifold was the source rom the front carb and the nipple closest to the radiator is for the tube/hose to the vacuum switch/relay.

[Dick Boneske]

Yes, this setup was from an automatic trans car. The long ball stud on the bottom of the center carb lever and the hot idle compensator on the rear of the center carb are evidence of that. It is true that on automatic trans cars, ported vacuum was routed from the center carb to the vacuum advance on the distributor. The longer, damaged line in one of your last photos is that line. The shorter line in your picture is the one that routes from the thermostatic vacuum valve front nipple to the vacuum switch on the center carb. You can move the vacuum hose on the thermostatic vacuum valve to the rear nipple.

I just now noticed the heater hose nipple assy. has a 45 degree fitting screwed into the manifold that supports the brass heater shutoff valve. There should be another right angle steel pipe that connects to the smaller of the two heater hoses. Normally I've only seen the 45 degree fitting on GTO's, but maybe it was used on big Pontiacs with A/C.

I can supply the 90 degree pipe for the heater hose connection and the short 90 degree tube that installs in the airhorn of the front carb and connects via a short rubber hose to the vacuum swatch. I believe I also have the longer steel tube that connects the vacuum switch to the diaphragm on the rear carb. PM me if you want to pursue further parts or info.

[bill ryder]

The dr. side

pass side

Bill"!

[68lemans462]

I ended up finding more info and got most things sorted out (I think)! I'm quite sure the small tube between the center and rear carb isnt in the right spot and I still havent figured out how that ported vacuum tube routes but other than that this is looking better!

[pfilean]

Note that picture shows both the ported vacuum application (part 28) for use in big car with Roto HM and non ported (hose 66) for big car with 4sp HM or GTO.

The vacuum pipe to the actuating diaphragm (part 79) is shown as running high between the front and rear carbs.

You have a nipple for PB off the back of the front carb. There was usually a pipe from there running along the left valve cover and turning toward the brake vacuum but I'm not sure you would have to supply that for a sale. Although it was a tri power only item from that front carb.

You have the link between the front and rear throttle levers as shown inthe picture. But I can't tell if there is a little interference with it and the choke tubes. You could possible reverse the ink to move it closer to the carbs.

Here is a couple pictures of a 64 but I can't vouch for the accuracy.

[pfilean]

And a few 1965 but again I can't vouch for accuracy.