I have a 1967 Cutlass Supreme Convertible with a 330 and a Rochester 2GC 2BBL. I have owned the car for about 12 years and gradually been replacing components/systems. The motor looks original but it has a TH400 behind it so who knows the true history.

The carb has never been great but the car has started and run well since I have owned it. I could never really step on it without a stumble but as long as I was gentle - no problems. I have essentially been enjoying it as a summer time cruiser taking my kids out for rides on weekends. Unfortunately, the carb began leaking this Fall and I was hoping for and easy fix so I tried a remanufactured carb from Summit.

The first unit flat out did not fit (I couldn't get anything to line up) so I returned it for another.

The second unit bolted right up and it starts and runs fine in Park but once I put it in Drive and hit the pedal, it stalls. I have researched the mighty interweb and have made multiple attempts at adjusting it but still no luck.

Both Summit units came with a 1/4" inlet line and my carb has a 3/8" line (first suspicious issue) so I swapped the fuel inlet to accommodate the 3/8" line on the new carb but still no joy.

Ok - I know everyone like numbers so here goes:

The number on the carb tag is 7037052 but I have no idea if it is original.

Engine number by water pump - 394417 3

#4 Heads - The VIN on the protect-o-plate matches the car and indicates the heads are W472288G but I have been unable to locate this number on the heads themselves (I haven't disassembled that far).

The only potential "performance" upgrade is a Pypes 3 in dual exhaust with X-pipe - sounds great!

So I am considering trying a re-build kit for my 2GC but after reading all the posts on this site, I am concerned that perhaps my current carb (and Summit replacements) are not correct for my application and the rebuild wouldn't be much better.

I would appreciate any recommendations to help further diagnose the problem I am having or point me in the right direction.

I have basic remove and replace automotive skills. I have replaced things like the starter, alternator, convertible hydraulic cylinders, and performed tune-ups but I have never "rebuilt" anything.

 

Welcome, I moved your post as the newbie forum is not really for troubleshooting it's for intro's. So at your leisure post an intro with some pictures of your car.


You say your car has a T400 in it. Do you know if it's a switch pitch? On the 2gc replacements, your throttle linkage should be adjustable and if it fit one it should fit another. It's also a very easy carb to rebuild.


The carb, 7037052, is for a 67-330. So it can be correct for your car. The engine code is for a 67-330 also.

 

Welcome to CO.
If you can find a rebuild kit,
they are not that hard to rebuild.
The kit should come with all the info
you need to do the job. I can't help
you on the #'s. But someone will chime in.

The one thing it won't come with will be the
carb vat. Berrymans makes a nice one that I
like to use, Comes in a paint can style bucket
and has a strainer cup. Very important to soak
parts overnite. Good luck and let's see some pics.

 

Welcome aboard. I can't help with the carb but I noticed this in your description of the car:
That number should be stamped on the end of the passengers side cylinder head. If the heads were ever taken off and not put back on the same sides, it would be on the rear of the drivers side head.

This site has a picture of the stamping and a decode for the numbers:
http://www.oldsmobility.com/old/engineid.htm

 

I have a 1967 Cutlass Supreme Convertible with a 330 and a Rochester 2GC 2BBL. I have owned the car for about 12 years and gradually been replacing components/systems. The motor looks original but it has a TH400 behind it so who knows the true history.

The carb has never been great but the car has started and run well since I have owned it. I could never really step on it without a stumble but as long as I was gentle - no problems.
==============
Accelerator pump petered out. Its job is to get you through that transition. Super easy fix.


I have essentially been enjoying it as a summer time cruiser taking my kids out for rides on weekends. Unfortunately, the carb began leaking this Fall
===============
Leaking what where? Leaking gas out the top is a problem. Also an easy fix.



and I was hoping for and easy fix so I tried a remanufactured carb from Summit.
==============
$$$
This is one of those occasions when having an experienced person rebuild your carb with or without you along to learn is the best route.



The first unit flat out did not fit (I couldn't get anything to line up) so I returned it for another. Both Summit units came with a 1/4" inlet line and my carb has a 3/8" line (first suspicious issue) so I swapped the fuel inlet to accommodate the 3/8" line on the new carb but still no joy.
===============
You don't say?! Non-original parts did not just fall into place and hook up w/o difficulty?
:-)



The second unit bolted right up and it starts and runs fine in Park but once I put it in Drive and hit the pedal, it stalls. I have researched the mighty interweb and have made multiple attempts at adjusting it but still no luck.
==============
Same symptom? Huh. with engine off, look down the carb, open the carb, and observe two strong streams of gasoline spraying into the bores. That's the accelerator pump. It is not unheard of for a rebuld kit to contain the wrong length accel. pump, and if the builder is not keen to detail, but just replaces old with new, it causes problems. Been there, done that, myself.



Engine number by water pump - 394417 3
#4 Heads - The VIN on the protect-o-plate matches the car and indicates the heads are W472288G
===============
Interesting
The block looks like '67 330, yet it has a TH400 trans? And I thought the W...G engine was the High Compression 4-bbl.


So I am considering trying a re-build kit for my 2GC but after reading all the posts on this site, I am concerned that perhaps my current carb (and Summit replacements) are not correct for my application and the rebuild wouldn't be much better.
==============
Proper carb, properly setup, will perform properly. That's the way they were built. There are, alas, a LOT of ways to disturb a carb's various settings until it's so far from proper that it's a pain to use.


I have basic remove and replace automotive skills. I have replaced things like the starter, alternator, convertible hydraulic cylinders, and performed tune-ups but I have never "rebuilt" anything.
===============
What is a carb rebuild, but replacing a lot of little parts?
OK, well, it's a thorough cleaning, which never hurts. fixing sloppy throttle shaft if it's really bad- I have never seen one that bad. And..... bending/ tweaking/ adjusting a dozen little links or whatnot per the instructions in the kit. For your FIRST carb, it would be wise to have an experienced guide. Pay attention to detail.... for example, the accel. pump... measure the old one in any way that might matter- overall length, position of the seal cup with respect to the top end of the rod, etc. Make sure the one that goes in matches that, even if you have to use the old rod and put the new cup seal and spring onto it. Then, during assembly, verify that the pump sits properly in its cavity- it's pretty basic... does the seal sit at the top, then travel to the bottom during use, bottom out, and the secondary spring then allows the driving link to continue to move though the pump is now stationary at the bottom of its cavity? It's always possible that someone put the wrong part in before, so checking that it seems to be operating correctly is a good idea.

Use proper fitting screwdrivers for all screws. Grind to a proper tight fit as necessary.
Do not be afraid to make special tools to suit. E.g. Fat blade screwdriver with a notch in each side, leaving a tang that centers the tool in the inlet seat, so it cannot slide aside and muff up the brass... Your Dremel cutoff wheel is indispensible for this toolmaking.

I have seen 2-bbl carbs [factory NOS] on several cars, with a slot or gap in the gasket that goes between the base and the main body. This gap lets unfiltered air into the engine. I would advise deviating from the factory practice in this case, and NOT allowing unfiltered air into the engine. Use the gasket that seals all the way 'round.

 

Thanks for the feedback everyone. Some answers to your questions:

Oldcutlass -
How do I determine if the trans is a switch pitch? And what does that mean?
The replacement carb that didn't fit was actually 1/8" too narrow - I couldn't connect the choke stove and throttle linkage (think the throttle was bent)

Octania - Carb started leaking out of the air horn gasket.

Fun71 - I found the engine ID on rear of the drivers side head - X331918. For some reason I thought this would be the head ID - is that stamped anywhere?

The heads have obviously been off - I also just noticed that scribbled in pencil on page 2 of the Protect-O-Plate: "rebuilt at 93,600 miles" (that explains a few things)

So it sounds like rebuilding the old carb should do the trick. Any recommendations on where to procure a good rebuild kit - more importantly with good instructions?

 

If you get the numbers off the data tag we can tell you if it's a switch pitch trans. A carb kit can be had through your local parts store they cover a wide range in carb part numbers.

 

Trans code is 76-OC-64986 (I am guessing that means it is of 1976 vintage)

I also have an extra Trans - OC-68-19846. Both will need to be rebuilt. The one in the car likes to burp trans fluid out the dip stick if it hasn't been driven for a couple weeks. The other has been sitting in my garage for 6 years. It would be nice to know if one is better than the other.

I also have a Q-jet - 7043250. I have been reading about the 2BBL to 4 BBL swap. A lot more work but perhaps it would be worth it.

Both the trans and the Q-jet were given to me by a neighbor who was kicking his old car habit.

 

My chart does not go to 76 but based on the earlier years it was behind a 400 or 455 engine low comp.


The other is a 68 that was behind a 455 also low comp.


Do your trans's have a short tail shaft?


To swap your carb to a 4V you need to change the intake manifold.