1970 rochester carb question

[Bill B.]

I have a 1970 small block 300hp auto, built on 5-14-70. The date code is 4 digits that i dont understand. Can someone tell me what my 4 digit date code should be?
Thanks,
Bill

[Edward J.]

Re: 1970 rochester carb question

Bill the first three digits are the julian date (1-365) the last is the year of manuf.

[Bill B.]

Re: 1970 rochester carb question

Ed, can I then assume that all 1970 corvettes the rochester carbs all end in 0? I dont know that I understand the "julian" date code...

[Brady C.]

Re: 1970 rochester carb question

Bill: go to page 60 in the 70-72 judging manual and will all make sense.....

[Bill B.]

Re: 1970 rochester carb question

Hi Brady, i have a service replacement carb, i'm currently looking for a correct one. I know the model # should be 7040202- i have seen a few for sale, but the date codes make no sense. Since my build date is May 14th, should my date code be 1340: or maybe 1349 in case it was produced in 1969?

[Mike E.]

Re: 1970 rochester carb question

Bill the first three digits are the julian date (1-365) the last is the year of manuf.

Except for the Carter-built quadrants. JG will help with those, too. Either is correct

[Terry M.]

Re: 1970 rochester carb question

Bill,

If your trim tag shows E14 it is unlikely, but not impossible that your carburetor was assembled in calendar year 1969. You ignored the reference to the TIM&JG that Brady posted. Is there a chance you don't have a judging manual?

I would wager if you google for Julian Date you can find a butt load of information, but there is no substitute for the judging manual for Corvette specific information.

[Bill B.]

Re: 1970 rochester carb question

I have a judging manual- i think i figured it out- thank you all...

[Brady C.]

Re: 1970 rochester carb question

Bill: To be safe any date from 1st of the year till your build date 001-134 would seem to be safe - so one dated 0010 - 1340 would work.... i have several extras but i have the NA9 option so need the # 502 so can't help you..... Look around as these are fairly common.

good luck and hope to meet up one day... planning to attend TX Regional in October..... work on improving that flight score!!!

[Bill B.]

Re: 1970 rochester carb question

That's what I figured as well. Hope to meet as well, good luck in texas- I'm going for my 1st flighting @the delaware valley chapter show in PA in october...

[David L.]

Re: 1970 rochester carb question

The 1970 Rochester 4bbl carbs came with two different date code systems. Carter also made them for Rochester.

In my "collection" I have the following:
7040203 2619 (261st day of 1969 for M.T.), Rochester
7040203 A0 (Jan. 1970 for M.T.), Carter
7040202 2749 (274th day of 1969 for A.T.)
7040208 0830 (83rd day of 1970 for truck)

I have seen the following "in my travels":
7040202 J9 (Sept. 1969)
7040202 E0 (May 1970)
7040502 1730 (173rd day of 1970, A.T., Calif.)
7040208 0930 (93rd day of 1970, for truck)

As far as I know the 1970 Camaro SS350 w/M.T. was issued the 7040203 (1st design) and 7040213 (2nd design) 4bbl carbs made by Rochester or Carter. The Rochester and Carter 1970 4bbl carbs look identical except for the name.

Were 1970 Corvettes only issued 4bbl carbs made by Rochester?

Dave

[Bill B.]

Re: 1970 rochester carb question

David,
When you say you have seen some of these "in your travels", i'm assuming that means you don't own them... I'm interested in that carter 7040202 dated E0 (May 1970); any details you can tell me about it?
Thanks,
Bill

[David L.]

Re: 1970 rochester carb question

David,
When you say you have seen some of these "in your travels", i'm assuming that means you don't own them... I'm interested in that carter 7040202 dated E0 (May 1970); any details you can tell me about it?
Thanks,
Bill

Bill,
What I mean by "in my travels" is auto swap meets. I saw the 4bbl Rochester Quadrajet carb stamped "7040202", "E0", and "DH" at the regional NCRS swap meet in Cypress Gardens in Florida on January 22, 1994. The asking price was $250. Needless to say I did not buy it. I only spend $10 to $20 for carbs. The carb had the following casting numbers:
top section: "7038388"
center section: "7038524"
base: "7038405"

I spent a few minutes this afternoon looking for my 1970 Quadrajets but only found two of them. I have at least 3 or 4 more 1970 Quadrajets somewhere in my "collection".

carb #1: casting on left side center section: "ROCHESTER" and "QUADRAJET"
stamped "7040202", "DH", "3199" (319th day of 1969)
center section castings "7038524" in circle, "GM", "RP" logo, "MADE IN USA"
base casting "7038405" in circle

carb #2: casting on left side center section: "QUADRAJET" and "MFD. BY CARTER CARBURETOR FOR GMC"
stamped "7040203", "A0" (Jan. 1970), and "DB"
center section castings "7038524" in circle, "K39" in circle (date code Oct. 3, 1969???), "R" in circle, "C" in circle, and "MADE IN U.S.A."
base casting "7037600" in circle

I also have the Delco Rochester bulletin 9C-3050 (dated Nov. 1971) for the 1970 Chevrolet, Chevelle, Nova, Camaro, Corvette Model 4 MV Quadrajet which shows illustrations and part number for all the individual parts. Sent me a PM if you want a copy.

Dave

[Bill B.]

Re: 1970 rochester carb question

Thanks Dave,
If you ever come across one that is numbered 7040202 and is dated 0010-1340 I'd be very interested in it... Or a carter that is coded AO-EO, that would work as well...
Bill

[David L.]

Re: 1970 rochester carb question

Bill,

The 7040202 carbs are a lot more common then the 7040203 carbs as most 1970 Chevrolets with 350 engines w/4bbl card had automatic transmissions. The reason why I bought the 7040202 carbs was price ($10) and spare parts. I am still looking for a 7040213 carb dated May or June 1970 for a 70 Camaro SS350 w/M.T. According to the 70 Corvette AIM GM # 7040203 was replaced with GM # 7040213 on 3/25/70.
I have seen 7040213 carbs dated C0 and D0 "in my travels". The 70 Camaro AIM only lists the 7040513 carb (2nd design,California).

Dave