[unruhjonny]

Wow, for the second time in this thread, I get am email for a post, come here, and it's not there... weird.

Originally Posted by jrunner

I don’t think if you poked a small hole in the plastic to check the numbers would make the value any less. At least you would be able to confirm what you have and WE would just envy your find more. Good score I remember when they were packaged like that. How time fly’s

I agree that a small hole shouldn't affect the value.

[70TA-RAIII]

Me too. I thought maybe he deleted his post or something.

[unruhjonny]

even if he did, I thought it was a good enough post to quote and agree with it.

Funny thing is, of all the forums I have ever been on, this one is the MOST restrictive in a users ability to delete or modify their own postings - yet that's probably what this is about.

It's a pet peeve of mine when I go to a thread I'm following, and notice a day or three later that I've made a typo which (often) makes my post hard to understand, yet I cannot correct it.

[Joe's Garage]

Originally Posted by Jimbobeast

BTW, the choke pull-off on OP pics is mounted 180° wrong, making airvalve action less than optimal.

Please explain above

I think Kenth is saying that it is mounted upside down (180* off).

It just needs to be removed, turned over so the nipples are reversed and reinstalled.

The pulloff should be getting its' vacuum thru the nipple that has the cap and the one with the hose should be capped.

It most likely changes the geometry of the choke / secondary flap linkage.

I'm sure Kenth will clarify when he gets a chance.

[Jimbobeast]

Originally Posted by Joe's Garage

I think Kenth is saying that it is mounted upside down (180* off).

It just needs to be removed, turned over so the nipples are reversed and reinstalled.

The pulloff should be getting its' vacuum thru the nipple that has the cap and the one with the hose should be capped.

It most likely changes the geometry of the choke / secondary flap linkage.

I'm sure Kenth will clarify when he gets a chance.

Ah, grasshopper, all is now clear.
And since the vacuum pulloff is wrong for a MT 1970 Ram Air car anyway, it will be replaced. Actually this frankencarb will return to the shelf and I will use the NOS "not-in-plastic" 07040263 1970 MT Service Replacement carb instead. It will be visibly correct, just missing that darn "7" in the stamping.
Does this carb (07040263) now look externally like a correct 1970 RA MT carb?

[Jimbobeast]

[QUOTE=Joe's Garage;6290346]This is a general response to both of the above posts.

The vacuum source on the carb was the tree on the back of the quadrajet, which also fed vacuum to the power brake booster and to the controls for the air conditioning on A/C vehicles.

Joe,
Do you have an illustration of the vacuum "tree" and do you have any idea where I can get one?
Thanks,
Jim

[unruhjonny]

Originally Posted by Jimbobeast

... I will use the NOS "not-in-plastic" 07040263 1970 MT Service Replacement carb instead. It will be visibly correct, just missing that darn "7" in the stamping.
Does this carb (07040263) now look externally like a correct 1970 RA MT carb?

To the untrained eye all 67-69 & 1970-Federal Pontiac Quadrajets look the same - so in that regaurd, I wouldn't sweat any of these little details (including the vacuum pull off).

I will stick my neck out to dare to say that the pictured carb went through a rebuilder of sorts in the 1980's, and is not NOS.
1) It has torx(sp?) head screws that only showed up in the 1980's around the time that computers started showing up to aid in ignition and/or fuel management - when that carb was manufactured they still used the flat head screws on the airhorn.
2) The fuel bowl vent tube has been reinstalled backwards.
3) The weighted choke mechanism looks to be a 1971-1972 style part.

For comparison, here are 273 and 263 carbs (mostly head-on):





Most people wouldn't be able to tell them apart.

Here is a 1968-1970 choke mechanism (it's pressed to the bracket that holds the choke pull off):



Here is as 1972 carb to show the difference betwen the weighted end of the choke mechanism.



Again, these are all small details, but details that most people will miss, and another reason why I wouldn't sweat it if I were you.

[Jimbobeast]

OK, getting closer. I think I have the correct weighted end of the choke mechanism to swap, and the torx screws are easy to replace. How difficult is it to remove/rotate/replace the fuel bowl vent tube?
I hope you don't mind me picking your brain for this minutia, but now it's become interesting.

[unruhjonny]

I haven't figured out a way to remove it from the top that will not mark it up;
It's best to push it out from the inside.

[padgett]

OK here is a NOS 7040263 mfd in 1973 (no leading zero).

[70TA-RAIII]

Great thread on these early carbs. Always looking to understand the differences between the 263 and 273 (and others).
Don't forget the little rubber boot for the accel pump shaft.

[Joe's Garage]

Joe,
Do you have an illustration of the vacuum "tree" and do you have any idea where I can get one?
Thanks,
Jim[/QUOTE]

Do you have A/C or any other vacuum accessories on your car?

There are trees with two and with three fittings, each with one large nipple (for the power brake booster) and then either one (without AC) or two (with AC) smaller nipples.

Here are pics of a couple of variants.

The larger, (sometimes angled) nipple aims at the brake booster.

The small nipple aiming towards the driver is for the vacuum advance TCS solenoid.

The 487331 fitting with the 2nd small nipple towards the passenger is for the AC controls (going from memory).

There are several companies with reproductions.

[Jimbobeast]

Understood. My car is a RAIV, therefore, no AC.
So, if I understand all this, vacuum for the ram air flappers comes from the top of the intake manifold, and vacuum for the TCS solenoid (and from there to the distributor) comes from the smaller outlet on the tree. The bigger tree outlet goes to the brake booster and voila ! C'est finis!
I will start hunting for one-armed trees.
I love it when a plan comes together.

[Joe's Garage]

For your RAIV application:
Vacuum for power brakes from the large nipple on the tree. The hose is also clamped to the back of the throttle bracket.
Vacuum to TCS solenoid, and then to distributor from the small nipple.
Vacuum for hood flappers from fitting in top of runner for #1, to the thermostatic switch in lower shroud, then to upper shroud and splits to the pods.

Flapper vacuum source (blue circle) is the closest to the front and lower of the two vacuum fittings on the intake. It's offset towards the driver's side slightly (~1.5").

The upper threaded hole (red circle) is for the unique PCV fitting that feeds fumes into both planes of the intake manifold. It's just in front of the carb and more centered than the other fitting.

[Jimbobeast]

Originally Posted by padgett

OK here is a NOS 7040263 mfd in 1973 (no leading zero).

I'm confused (not an unusual experience for me):
If it's a 1970 carb and NOT a service replacement, how could it be manufactured in 1973?

[Jimbobeast]

There are trees with two and with three fittings, each with one large nipple (for the power brake booster) and then either one (without AC) or two (with AC) smaller nipples.

Here are pics of a couple of variants.

The larger, (sometimes angled) nipple aims at the brake booster.

The small nipple aiming towards the driver is for the vacuum advance TCS solenoid.

The 487331 fitting with the 2nd small nipple towards the passenger is for the AC controls (going from memory).

There are several companies with reproductions.[/QUOTE]

Got it
Ames Part # N139PT (two nipple)
N139PX (three nipple)

[unruhjonny]

Originally Posted by Jimbobeast

I'm confused (not an unusual experience for me):
If it's a 1970 carb and NOT a service replacement, how could it be manufactured in 1973?

It is a service replacement part.
You can tell by:
1) it lacks the pick code
2) the date code is for after the 1970 model year.

Maybe you're confused about the "NOS" designation(?);
NOS = New Old Stock
Depending on the context in how the term is used, it can mean a couple things, but generally NOS is there to suggest that it's a brand-new/never-used part, which has sat, completely unmodified for a very long time.

I some NOS parts;
they vary in age and application, but they all share the fact that they have never been installed or used - any possible dust aside, they are effectively brand new parts.

[padgett]

Well sorta (holy war). OEM (original equipment manufacture) is what was installed at the factory. NOS (new old stock) is an over the counter part. A carb in plastic and a Delco box is NOS and not OEM. Date codes only really matter for OEM.

Back in the day it was common to mix and match parts to create a 800 cfm QJ from 750 cfm parts and adjust rods and jets to suit. In the emissions era plastic caps were placed over the idle mixture adjustments to prevent "adjusting". When was the last time you saw those ?

For that matter no car (unless an accident happened) ever left the assembly line with a R59 battery. Believe it or don't.

[Kenth]

Originally Posted by Jimbobeast

BTW, the choke pull-off on OP pics is mounted 180° wrong, making airvalve action less than optimal.

Please explain above

The connection on pull-off that has delayed action, like any other pull-off has, goes to the carb and the other non-dampened connection goes to the vacuum tank and delayes chokeblade breakopen at cold starts even more.

How the pull-off should be mounted is clear when you look in which direction the connections are directed.

This choke delay system was used only on 1970 Pontiac non-RamAir and Cadillac Quadrajets.

[Baron Von Zeppelin]

Originally Posted by Jimbobeast

If it's a 1970 carb and NOT a service replacement, how could it be manufactured in 1973?

The carb Padgett pictured is a Service Replacement.
And also happens to be NOS (un-used)

Your SR having a zero leading the application number is unusual, but has its explanation - due to its timeframe.

In contrast, have seen other application numbers for 69-70 model SR carbs with mid-to-late 70's production dates - without a leading zero. Most do not have it.

Nothing to worry over either way