Which Rochester 4 barrel carburetor to choose

[Sascha P.]

Today I have discovered that my 1973 454 manual transmission Corvette has a carburetor for a 1972 454 engine. Installed is a Rochester 7042211. After a search on the internet I have found that the following should be installed on my car: Rochester 7043201.

I removed the carburetor because I wanted to rebuild it. My question now is if there are any known differences between the mentioned carburetors. Shall I rebuild the 7042211 carburetor or shall I purchase a 7043201? I am not an expert and I do not know the differences between those two.

Thanks in advance,
Sascha

[Joe L.]

Re: Which Rochester 4 barrel carburetor to choose

Today I have discovered that my 1973 454 manual transmission Corvette has a carburetor for a 1972 454 engine. Installed is a Rochester 7042211. After a search on the internet I have found that the following should be installed on my car: Rochester 7043201.

I removed the carburetor because I wanted to rebuild it. My question now is if there are any known differences between the mentioned carburetors. Shall I rebuild the 7042211 carburetor or shall I purchase a 7043201? I am not an expert and I do not know the differences between those two.

Thanks in advance,
Sascha

Sascha------

The 7042211 carburetor was originally used on 1972 Chevrolet pick-up trucks with 350 cid engine. My guess is that your car once had its carburetor replaced with a rebuilt carburetor that used the 7042211 as a core. Commercial rebuilders often use cores from different original applications as the base to build up a carburetor for another application. So, I would expect that, functionally, the carburetor is fine for your application.

However, from a "correctness" point of view, important if NCRS or NCCB judging is in your future, the carburetor is not correct and will cost significant judging points. If this is important to you, then I'd try to obtain a correct core of GM #7043201. Then, rebuild that to the original specifications of the 7043201 carburetor. In looking for a correct core, you'll also want one dated within 6 months prior to the car's build date.

[Clem Z.]

Re: Which Rochester 4 barrel carburetor to choose

7042211 #43 rod, #74 primary jet, DA secondary rod. 7043201 #48 rod, #77 primary jet, DA secondary rod

[Patrick H.]

Re: Which Rochester 4 barrel carburetor to choose

The 7043201 appears to have been used on many different Chevrolet models. As a result finding one, and even one with a good date, should not be that difficult.
I'd at least start to search for one.

[Sascha P.]

Re: Which Rochester 4 barrel carburetor to choose

Hello Clem!
Thanks for your response but I am not sure about your answer. This is the first time I am going to work on a carburetor. I assume that your are suggesting to buy the listed parts to use them with the carburetor but I am not sure. Maybe you can explain a few more details regarding your response.
Regards,
Sascha

[Michael W.]

Re: Which Rochester 4 barrel carburetor to choose

Sascha-

Unless you're going to enter formal judging events, there's no need to change carbs. It's more than likely that some rebuilder some time in the car's past converted your existing carb to suit the needs of the engine so in function you already have the 'correct' carb. The numbers that Clem provided could be compared to the existing needles and jets in your carb to confirm.

As to rebuild kits, make sure that all components used are compatible with E10 gasoline. There were some less than forthright retailers up until recently that were selling outdated accelerator pumps that quickly deteriorated in the presence of ethanol.

[Clem Z.]

Re: Which Rochester 4 barrel carburetor to choose

Hello Clem!
Thanks for your response but I am not sure about your answer. This is the first time I am going to work on a carburetor. I assume that your are suggesting to buy the listed parts to use them with the carburetor but I am not sure. Maybe you can explain a few more details regarding your response.
Regards,
Sascha

i just listed the parts so you can see what you have when to rebuild your carb

[Sascha P.]

Re: Which Rochester 4 barrel carburetor to choose

I see, thanks.

Regards,
Sascha

[Dennis O.]

Re: Which Rochester 4 barrel carburetor to choose

Even if you're not interested in having the car judged, I would try to get a correct numbered, dated carburetor if the are as easy to find as these folks seem to indicate. (I don't know much about Rochesters, having a '67 L79). If you want to sell the car down the line, a correct carb would be a good plus. I am just now trying to find a correct dated Holley for my '67 (it has a later replacement), and am shocked at the prices they now command.

[Sascha P.]

Re: Which Rochester 4 barrel carburetor to choose

Thanks for all the responses. Now I have attached a picture of the right side of the carburetor. The part that should hold the chocke (if I am not wrong) is tied up with a peace of wire. I find it difficult to find out which part is really missing. Maybe someone has input for me. I would also appreciate any recommendations for websites or books that explain rochester carburetors in detail. I know that amazon provides a few books but it is diffucult for me to choose a good one.
Thanks a lot, Sascha7043211_right_view.jpg

[William C.]

Re: Which Rochester 4 barrel carburetor to choose

You are missing the choke pull-off, a vacuum device that opens the choke slightly when the engine starts. Do you have the link from the heat activated spring in the manifold to the choke?

[Sascha P.]

Re: Which Rochester 4 barrel carburetor to choose

Thanks William, I have got no idea. How would I identify that? I have got many pictures, could you see it if you would get the right picture?

[William C.]

Re: Which Rochester 4 barrel carburetor to choose

OK, I'm trying to attach a scan of a typical Q-Jet from the 70's exploded view, along with a key to the names of the numbered items. If this doesn't work on the board, email me at "wclupper@neo.rr.com" and I'll send them via return email.74Q-jet1 001.jpg001.jpg

[Larry M.]

Re: Which Rochester 4 barrel carburetor to choose

Sascha,

Here is a scan of a page from M. F. Dobbins' 'Fact Book of the 1973-1977 Stingray', showing carburetor details, which may be of help to you.

Larry



scan0001.jpg

[Larry M.]

Re: Which Rochester 4 barrel carburetor to choose

The photos from the full-page scan may be too small and indistinct to be of use. Here they are individually.

scan0002.jpgscan0003.jpgscan0004.jpg