1970 carburator

66 ponchoboy · Veteran Member

1970 carburator

birdsandgoats · Veteran Member

What engine and trans does your car have . I have a few carbs used and rebuilt

HK1837 · Addicted!

Are you sure that number is right? The only 703 Quadrajets I have seen are the California spec 1967 smog carbs. After 1967 I thought they all reverted back to 702 then 704 then 1705 etc. I would have expected a 1970 carb to start with 704026x or something like that?

norontcan · Canadian Poncho Superstar!

For 1970 I believe the 4th last digit would be 0 ( zero )

unruhjonny · Guru

I believe you have the wrong application number listed.

Maybe you found a casting number, or a Rochester kit of some sort?

I have only seen "703" for pre-1968 application numbers or for casting numbers.
If this was indeed an application number the "6" in 7036912 would suggest this is a 1966 application unit, which would be from the very first lot of them;
Generally first year Quadrajets are considered to be 1967, but I have understood that there were a couple Chevrolet specific applications of a 1966 Quadrajet.

The '912 also seems off;
Generally the fifth and digit (7036912) is a general application identifier (eg: non-GM, or 2bbl vs 4bbl);
Generally the sixth digit is a divisional identifier;
And the only instances where I have seen "91" used in these two identifier locations were when they were for after the fact service replacements intended to cover a variety of applications - typically a modified post-1974 fuel bowl setup to replace an earlier casting after the early design fuel bowls were no longer being manufactured.

A 1970 Chevrolet Quadrajet should be 7040X0Y, 7040X1Y or 7040X2Y;
Where "X" is general identifier; 2 = non-Ca; 5 = California
Where "Y" is the application identifier; typically an even number means an automatic, and an odd means a manual - but there are exceptions to this rule.

I believe that the full list of 1970 Chevrolet Quadrajets is as follows:

7040200, 7040201, 7040204, 7040205, 7040221 = Big block car non-Ca applications

7040500, 7040501, 7040504, 7040505, 7040521 = Big block car California applications

7040202, 7040203, 7040207, 7040213 = 350cid car non-Ca applications

7040502, 7040503, 7040507, 7040513 = 350cid car California applications

7040206, 7040208 = non-Ca truck applications

7040509, 7040511 = non-Ca truck applications

I just happen to have a 7040208 on kijiji right now.
I also have several Rochester books which help decode for application, or original jetting ect.

I just remembered I had one other book to consult;
I found eleven 7036--- application numbers, none ended with a 912.

-- Edited by unruhjonny on Tuesday 26th of January 2021 06:00:32 PM

HK1837 · Addicted!

He was after a GTO carb though, hence the suggestion of 704026x

73SC · A Poncho Legend!

66 ponchoboy wrote:
I need a Quadra Jet for a 1970 GTO I believe the carb number is 7036912.

#7036912 is specified for use with the Ram Air Induction non EES 1970 GTO 455 CID with Turbo 400 on page 381 of the Pontiac GTO Restoration Guide.

HK1837 · Addicted!

Very wierd. It breaks most Quadrajet numbering systems, but you are right, these are listed for 1970 Pontiac for various applications:

7036912, 7036913, 7036914 and 7036915.

The use of 703 must be part of the introduction of ESS, like it was in 1967 when the Californian smog Quadrajets had a 703 prefix.

68beaumont · Guru

For a 1970 non-California GTO/Tempest/Lemans 400 4bc w/auto trans the oe carb # is 7040270, with 7036912 being the service replacement carburetor. ( As per Rochester Carb Chart).

unruhjonny · Guru

HK1837 wrote:
He was after a GTO carb though, hence the suggestion of 704026x

Egads, how did I miss that!!

HK1837 wrote:
He was after a GTO carb though, hence the suggestion of 704026x

Again, my bad.

73SC wrote:
66 ponchoboy wrote:
I need a Quadra Jet for a 1970 GTO I believe the carb number is 7036912.
#7036912 is specified for use with the Ram Air Induction non EES 1970 GTO 455 CID with Turbo 400 on page 381 of the Pontiac GTO Restoration Guide.

Ok, in that case, that '703' number is a replacement service package number, not the carburetor application number;
Things can be a bit confusing, but GM used the same numbering system for EVERYTHING, these numbers were simply assigned as a number was required, so there is often no ryme or reason as to the order of things.
So, with this information at hand, I looked this up;
The package number 7036912 is a package number for a 7040270 carburetor.
This is the automatic application number carb used for 1970 Ram Air III & Ram Air IV engines, and I believe it was also used for some 70 GTO's with the 455 - but my 70-GTO-455 knowledge is a bit sketchy.

68beaumont wrote:
For a 1970 non-California GTO/Tempest/Lemans 400 4bc w/auto trans the oe carb # is 7040270, with 7036912 being the service replacement carburetor. ( As per Rochester Carb Chart).

Again, that is not a carburetor number, that is a "replacement package number", the number of the carb you seek is a 7040270.
Similar carbs you might want to look for (incase the buy in for a 7040270 is a bit too steep for your pockets) are either:
7040264 = 400/auto non-RA
7040262 = 455/auto non-RA
7029270 = 1969 RA/auto application, this application number seems to have been build in exponentially higher numbers - service replacement carbs of this number can often be had for $800usd and be all there.

Please take this to heart;
This application number is one that is often faked - people are renumbering Oldsmobile or Buick castings and selling them as Pontiac Ram Air units with little regard to anything short of the application number stamping looking authentic.

I have a 1970 'YZ' Ram Air III that came with my car when acquired in 1995;
I have attempted to keep it all together and correct, to that extent I have been looking for a reasonably priced 7040270 myself, but decided to settle for the next best of a different year Pontiac 400 Ram Air service replacement carburetor;
The first one I found was a 7028276 (service replacement for all 1968 RAI carbs - that was the final year where GTO and Firebirds originally had different application number RA carbs).
The next one I build around parts after I realized that I had a correct 69 RA throttle body, and SR RA airhorn; it's a 7029270 - I don't have too much into this one because I found the fuel bowl at a very reasonable price.

Not many people realize that rebuilders were notorious for mixing and matching similar parts, and adjusting donor carbs to be more generic - which is how I came to have the TB and airhorn for the 7029270.
Most Quadrajets these days have had parts swapped, so even some really nice looking units on the bigger online auction places have parts which have obviously (to the keen eye) been swapped out.

-- Edited by unruhjonny on Wednesday 3rd of February 2021 03:36:13 PM

66 ponchoboy · Veteran Member

thanks for this guys I bought one.

mfleury · Poncho Master!

I got quad card the number on it is 7028240

unruhjonny · Guru

mfleury wrote:
I got quad card the number on it is 7028240

that is a 1968 Buick carburetor.

702 = Quadrajet; pre-1970
8 = 1968
2 = federal application
4 = Buick
0 = application; generally "0" or even numbers designate an automatic application.

This carb will look very similar to a Pontiac Quadrajet, but the throttle arm is different, and you cannot swap a Pontiac throttle body on it - you can physically put it there, but it is a mismatch with the way that Pontiac and Buick Quadrajets are manufactured to run.