Captain Obvious

Excellent! Glad to help, and hope the rest of it goes smooth!

@BlueZee, Thanks for the excellent pics and the video. Another Z mystery solved. Thanks again!! SurferD, What that orifice does is bleeds the vacuum out of the diaphragm canister that pulls on the throttle after the throttle opener has been actuated. Goes like this... When vacuum goes really high (like when decelerating with foot completely off the gas), the vacuum control valve will open and allow vacuum to be applied to the servo diaphragm. When that vacuum is applied to the servo diaphragm, it pulls on the throttle linkage and holds the carbs open a tiny bit to limit the intake manifold vacuum. Once the intake manifold vacuum drops below a certain point (adjustable with a screw), the control valve will close and additional vacuum will not be applied to the servo. But the cavity inside the servo still holds vacuum, and that little bleed hole's job is to let that vacuum bleed off so the servo diaphragm can relax and stop pulling on the throttle linkage.

@BlueZee, Thanks for that pic! Kinda hard to tell for sure, but yes, that may be a bleed hole. if it is, it would be an answer to something that has bothered me for years. Does that hole actually go anywhere, or is it just a dent from the locking setscrew? Can you pass air through that hole?

I'm not currently running flat tops on my car, but I do know a little about them. I'll do what I can to help.

Naaaa... Most times I just make stuff up and usually people don't bother to check it. !!

Thank you kindly! Looks great!

Hope the rest of the project goes well.

They started with that upper part in 73. Prior years didn't have that. It's a solenoid valve that they use to disable the opener system when the car isn't moving. In other words... When you blip the throttle at idle sitting still, it won't let the opener pull on the linkage.

I can't make out both butterflies, but the one I CAN see is not what I would call "closed". Different cars need different amounts, but IMHO, that's open much further than idle. And some other weirdness, although I'm not sure it's related: 1) It looks like you're using 72 spacer blocks between the carbs and the intake manifolds, and they are upside down. I'm not sure that's causing you a vacuum leak or what, but if you're sucking air in there and then opening the butterflies to "compensate" maybe? 2) The linkage between the two carbs looks a little too short. Looks like the ball on the left side in the pic (front carb) is close to falling out of the receiving hole on the carb. I'm not sure what all the years parts you're working with here, but that's a problem that often occurs when there are 73 or 74 parts involved. I don't think you've got that, so I can't explain the issue there.

Of course!

Yup. That'll do it. ^^ On a side note, I think the whole idea of running the primary ignition current into the passenger area and to the tach is a bad idea. I guess at the time that was the best they could come up with. They didn't ask me though.

This is how the wiring diagram looks for 73 in the tach area. The two ignition connections (from the ballast resistor and then back out to the tach) are the GW and BW wires. On the back of the tach (on the tach;'s side of the connector) those colors are the white with the red and black tape stripes): So since they don't show the stub-off connectors between the gauges and the dash harness, (or any of the colors involved) it's hard to know for sure, but unless they pulled the ground signal through the metal tach case itself, then they ran four wires through the connector in that stub harness. However, as previously mentioned, I've never been deep into anything earlier than 74, so I would obviously defer to someone who has!

That said, however, I've not owned an early one either. I'm going off pics and documentation. Like that can never be wrong... By the time they got to anything I ever delved deep into, they had switched over to the newer voltage sensing tach. I believe that was 74.

Because on the early years they run the primary side of the ignition coil signal through the tach to provide pulses. That's the looped wire on the back of the "current sensing" tach. Now, it would be easy to bypass that and get the ignition to work without the tach, but if everything is wired according to stock, it shouldn't run without a tach installed:

Yes, that is to be expected for the early years.

Wow... That's tough to resist. I'm resisting so far, but it's tough.

The little door doesn't seal perfect. So, even if you had one, it's not like you won't be getting water in there. I mean, the less water the better, but even if the door flappy does work, it's still going to leak some. Good luck moving forward and hoping it works out easy!

I don't remember the minute details... Clearly from your highly detailed recollection of the other place, that's what I had you for. Something about the two guys were competing in the annual BBQ competition and were thinking they might win? Placed high previous year and thought they might take first place that year? They didn't want to recommend any Q from any of their competitors. They were not in the restaurant biz... One was a lawyer and the other was an a software guy or something? I bet they opened a BBQ joint after we met them. Any of that ringing any bells? Oh yeah, and their female companions were attractive. That's probably why you don't remember shitte.

No trouble on the air cleaner info. Regina the 3rd will see it eventually and speak up. He's a lurker. Says he's "busy" or some crap like that. I'll bug him again @GGRIII . Nice. They won't like getting crushed, but still probably thinner than the foam. The real trick would be to chuck up the dome or body in a lathe and cut an O-ring groove.

The results look promising but keep an eye on it for a while. Haha!! Nice! Just keep an eye on everything!

Easy if you the have hands of a surgeon.

Yes, it's supposed to have a little spring loaded door over the hole, but most of them have fallen apart over the years. The springs rust and it falls apart. If you're lucky, the door and pin is still there but has just fallen open (always open) so you can't see it. In other words, it's in there, but off to the side. The little rusty nub is what's left of the door spring:

That's not controversial to me at all. I completely agree 100%!! I'll check on those round air cleaner filter gizmos for you... Tagging @GGRIII . That's his car and he bought the air cleaners. I don't know where he got them, but I remember something about "cheap clones of the expensive ones". Hopefully he come in and shed some light. And hopefully they might be cheaper on your end of the pond as well.

So the glove box uses the same key as the doors? If that's the case, then I would agree that it sounds like the ignition lock was replaced. Not unusual at all. The hatch though... Seems a little unusual for the hatch to be replaced before the doors are. Maybe the hatch lock DOES use the same key as the doors and glove box. Maybe it's just all frozen corroded up inside. Taking the hatch lock out is not complicated, and after it's out of the car, taking the hatch lock apart is not difficult. It's probably one of the easiest. I'd take it out, clean it up, and see what it looks like inside. Failing that, a locksmith would make short work of the problem.

Haha!! Excellent! Then I've accomplished my mission! So you could try a bead of silicone once you're sure you've got everything else dialed in and hopefully won't have to be taking the domes off again every other day. More hidden than the foam. Just as long as there isn't some other second order effect from the foam thickness that makes a problem come back. In any event, it's just great to hear it's running so well and I'm happy for you! I think that turbo-esque whistle is the air blowing across the holes in the bottoms of the pistons. Like blowing across the opening at the top of a bottle, or a flute. I had never noticed it until the original air cleaner was replaced with smaller individual ones on each carb. I think the large mass of the original air cleaner housing and the fact that the stock input snout pointed forward towards the radiator muffled the whistle. And good work with the FBTT!