Rochester 2GC carbs

I'm running trip's on my car , 2 secondary carbs are older Rochester 2 barrels(1967) center one is a little newer( 1969) I'm wondering what my total CFM is?? Its a 400 CI SBC(Stock), it is under carbed?
JimV

 

No about 800 to 900 cfm just fine Jobob

 

I believe they are 273 cfm each ......

 

it depends, are the front feed (with a big filter nut) or side feed.

 

there all side feed

 

All of the small (side feed)2GCs that I had on the flowbench flow between 250-270 cfm.
That's with the small chrome louverd air cleaners with K&N elements.
The common chrome louverd air cleaners are VERY restrictive!
To fix that problem put a spacer on top of the element to lift the "hat" up about 3/8". That opens the small gap up around the bottom of the hat.
The rubber seal from a Fram HP4 oil filter works great as a spacer.
Do you know what I'm sayin'?
I can do some pics later if they would explain it better.
Have fun,Smokey

 

How do you identify which Rochester 2 jet carb you have? I have looked mine over and the only # I see is 7000285 on the bottom of the float bowl. They all have the same number and are set up on a progressive linkage. They work very well but I need to get some rebuild kits and am not sure exactly which model they are. This engine has been together for almost 40,000 miles. Sorry it looks so beat.
Thanks in advance
chuck

 

your probaly ok with cfm here depending on other motor mod gearing etc the GM fact 3x2 in 59 [except for chevy] went to the larger ends and smaller centers 350 cu - 400 cu i believe some later 60's gto"s and pont 421 HO's came with all large rochesters bottom line your 400 if modified would perform better with the larger ends and maybe with the larger center carb i've seen some offy 3x2 large bolt intakes around maybe try one and file the small center carb base mounting holes out to fit the larger pattern john

 

Copshopcoupe, I looked on the sheet that came in the rebuild kit for the 2Gs that I have.(Standard Motor Parts "Hygrade" Brand)
Your number is not there. Most of the numbers start with 70 but higher than yours. The closest is 707171(55 Chevy truck)
It ain't much but,I tried. Smokey

 

thanks, I will keep looking. I am going to try a local guy who rebuilds carbs and see if he will give up any info.
Thanks
Chuck

 

Hi.....I have a Man-A-Fre 4X2 intake manifold for a big block and want to find the kits for the carbs. All 4 are Rochester 2GC, and have the number 7011824 on the main body. Does anyone know the source or part numbers of the kits or where I can buy them...thanks guys

 

http://www.thecarburetorshop.com/

Try these guys.

 

How do you identify which Rochester 2 jet carb you have? I have looked mine over and the only # I see is 7000285 on the bottom of the float bowl. They all have the same number and are set up on a progressive linkage. They work very well but I need to get some rebuild kits and am not sure exactly which model they are. This engine has been together for almost 40,000 miles. Sorry it looks so beat.
Thanks in advance
chuck

If there small base rochesters the kits are pretty much universal. I recomend doing a search on Vintage Speed, it's a mom and pop shop, Charlie can answer any questions you got, good people to do business with.

 

This is a pretty good site for Rochester ID:
http://www.oldengine.org/unfaq/leadfoot/qjet1.htm

 

I have one of those in my hand, It still has the original Tag 7008005 is the Tag number, this page says it is for a '55 Chevy
http://www.trifive.com/garage/55 Chevy Assembly Manual/221-7.gif

 

Chuck R, that could be the float bowl number rather than the carb number.

This might help some

http://www.carburetordata.com/?id=21