Topic: 67 390 carb help

[Slawton4]

Hey guys! I'm going to post these questions in the most direct way possible rather than give a two page story... bare with me.
I have a '67 GTA 390 built 9/66 at SJ.  I found a carb that's almost correct that I want to have rebuilt.  Its a c70f-9510-a (list 3793) dated 6/66. I know it should be a c70f-9510-b (list 3794) but it seems like it might be close enough for now. My shop says the aluminum shafts are bent and non salvageable, and he's had no luck finding replacement shafts (Holley and another distributor were no help) but he did find a core he said should work.  My questions are:
1. Is this date code correct for my car? 
2. How many months before a vehicle build date is correct?
3. Has anyone else had this issue and found replacement shafts to use?
4. Are there any differences between list 3793 and 3794 besides the metering?
5. Who do you guys use for technical rebuild issues like this? 

Thank you all so much for your help!
Sonny

[Bob Gaines]

Hey guys! I'm going to post these questions in the most direct way possible rather than give a two page story... bare with me.
I have a '67 GTA 390 built 9/66 at SJ.  I found a carb that's almost correct that I want to have rebuilt.  Its a c70f-9510-a (list 3793) dated 6/66. I know it should be a c70f-9510-b (list 3794) but it seems like it might be close enough for now. My shop says the aluminum shafts are bent and non salvageable, and he's had no luck finding replacement shafts (Holley and another distributor were no help) but he did find a core he said should work.  My questions are:
1. Is this date code correct for my car? 
2. How many months before a vehicle build date is correct?
3. Has anyone else had this issue and found replacement shafts to use?
4. Are there any differences between list 3793 and 3794 besides the metering?
5. Who do you guys use for technical rebuild issues like this? 

Thank you all so much for your help!
Sonny

You must be wondering for when you find the correct carb given it doesn't matter if the date code is appropriate or not on a incorrect one used on your car that you are rebuilding now. The most economical place for parts is typically from a donor carb core and not trying to find individual parts for sale separate. Those carb cores are relatively plentiful still.

[Slawton4]

Ok umm.... thanks? I guess?

[RoyceP]

Typically the carburetor would be dated a month or perhaps six weeks earlier than the car in the case of a GTA390 Mustang which was relatively common.

Lots of decent rebuildable carbs on eBay. Buy one there and use the one that you have for parts.

Example: https://www.ebay.com/itm/Holley-Carburetor-Carb-C70F-9510-B-List-3794-Dated-651/283724779793?hash=item420f509111:g:3ncAAOSwZoVeBrK7

We don't know what date your car was built so unable to comment on what date carburetor you need. Try putting your car in your signature to avoid having to answer that question ever again.

Hey guys! I'm going to post these questions in the most direct way possible rather than give a two page story... bare with me.
I have a '67 GTA 390 built 9/66 at SJ.  I found a carb that's almost correct that I want to have rebuilt.  Its a c70f-9510-a (list 3793) dated 6/66. I know it should be a c70f-9510-b (list 3794) but it seems like it might be close enough for now. My shop says the aluminum shafts are bent and non salvageable, and he's had no luck finding replacement shafts (Holley and another distributor were no help) but he did find a core he said should work.  My questions are:
1. Is this date code correct for my car? 
2. How many months before a vehicle build date is correct?
3. Has anyone else had this issue and found replacement shafts to use?
4. Are there any differences between list 3793 and 3794 besides the metering?
5. Who do you guys use for technical rebuild issues like this? 

Thank you all so much for your help!
Sonny

[Slawton4]

Its actually in the original post... The second line.  But I'll add it to my signature, good idea.
If it matters, my car was built on the fist of September.  The carb on ebay you linked was built the first week of May... Would 4 months be considered close enough to be correct?

[67gta289]

Close enough for what?  For MCA concours, yes.  For TB, no. 

You have not provided enough information for a conclusive answer.   The term "correct" is often in the eyes of the beholder (often with a direct relationship with cash in the wallet)

[carlite65]

fyi....mca does not check date codes in the concours level of competition, only in unrestored and thoroughbred.

[Slawton4]

fyi....mca does not check date codes in the concours level of competition, only in unrestored and thoroughbred.

Close enough for what?  For MCA concours, yes.  For TB, no. 

You have not provided enough information for a conclusive answer.   The term "correct" is often in the eyes of the beholder (often with a direct relationship with cash in the wallet)

THIS is what I needed to know. Thank you!  So ultimately the date code doesn't even matter as long as the carb is correct? I was going to use the 3793 until I found a 3794 with the correct date.  Being an early build I had had some difficulty when looking before, but I see there is one on ebay at the moment. 

[67gta289]

For MCA concours date code does not matter

[Bob Gaines]

How many cars while judging in concours trailered are allowed to have the air cleaner taken off to even check engineering and list numbers to confirm correct application? 

[Slawton4]

Specifically regarding the aluminum shafts, has anyone replaced them with a sturdier metal?  I thought I remembered there being a carburetor guru on the forums somewhere.

[RoyceP]

Never had any trouble with throttle shafts. I just find a parts carburetor or another similar carburetor to rob parts from.


For example there are Ford versions of 600CFM Holley 1850-1 carburetors that have throttle shafts identical to your 1967 600 CFM Mustang Holley carburetor. You can buy a used 1850-1 for very little money because they are so common.

Specifically regarding the aluminum shafts, has anyone replaced them with a sturdier metal?  I thought I remembered there being a carburetor guru on the forums somewhere.

[J_Speegle]

Its actually in the original post... The second line.  But I'll add it to my signature, good idea.
If it matters, my car was built on the fist of September.  The carb on ebay you linked was built the first week of May... Would 4 months be considered close enough to be correct?

Maybe I missed something - nothing new  but where did the May date come from. Looking at the tag you posted  (6F) it suggests June

Given that your car was/is a very early car an the date of the first week of May suggests that they were building these carbs in groups (typical for Holley) way in advance of the production year - preparing for the new model. Because of this I think the date would be just fine

Was your car delivered to a 72 or 71 DSO dealership?  Asking since the carb tag shows it was for a non-thermactor car.

IMHO would not focus on what a judging event or rules standards are but what the level of restoration you have chosen and use that as your guide.Of course they could be one in the same or you can shot higher - a true full restoration and in that case you should do well if you choose to show the car along with reaching your personal goal

[Slawton4]

The May date was referring to the carb on eBay that it looks like I may end up getting. The tag in the picture is for the carb I already have which has the June date code.