Rochester Quadrajet rebuild?

[mw67rs]

I am putting a new engine and transmission in my truck. I am thinking about rebuilding the carb while doing this. The ID # on the carb is 7045583 which I think indicates it is for a 1975 for Checker or Marine with a manual transmission. If that is correct then this is not the carb that came stock on the truck. The truck is a '77 Chevy K10 with a TH350.

So my questions are, can I rebuild this carb and have it pass CA smog or do I need to get a carb made for my truck? My guess is that all the differences could be made up by installing a rebuild kit for a CA '77 with auto trans but I don't know for sure. Does anyone know if this is correct? Can I just go to Autozone and ask for a rebuild kit for my truck and rebuild the carb and have it end up working just like it was originally from the factory?

[lindstromjd]

The carbs set up for a manual transmission have different accelerator plunger specs than those for automatics. You'll over-fuel and bog down on acceleration until the engine catches back up with the fuel delivery. I would try to find one for an automatic and rebuild it. There are a lot more of them out there than there are ones for manual trucks. And they're not hard to rebuild, just clean the hell out of everything you can with car cleaner and a toothbrush and pay really, really close attention to your measurements and specs. Be anal about them or you won't run right.

[tucsonjwt]

Did your existing carb already flunk CA emissions? I thought old trucks didn't need to be smogged in CA. If you flunk with your carb as is, then I would check Sean Murphy for the rebuilt carb and cost. I got a cheap rebuild from Carburetor USA and had some issues, but finally got one to pass emissions in AZ - fuel economy is bad though.

[geezer#99]

According to my uncle Lars, your carb is factory stock.
Look half way down the page for the carb number specs.
http://www.digitalcorvettes.com/foru...ad.php?t=88376

THen if you need to rebuild it, buy a super quality kit from Cliff.
http://www.cliffshighperformance.com/carbkits.html

[mw67rs]

Thanks Geezer, I found my carb number on the page you listed and see it is for 75-77 so it looks like the year is correct. I couldn't tell from the information on that page if it was for an automatic or manual transmission.

I was looking at this page http://www.cliffshighperformance.com...carb_ID_2.html to decode the carb. It says that if the last digit is odd it was for a manual trans and the last digit on my carb is odd. So that is what makes me think it is for a manual not an automatic. But it also says that it is for a 75 but the info you found says 75-77. So I am not to confident in this decoding.

Do you know if my carb is for use with an automatic transmission?

[geezer#99]

Best way to tell is if your carb has the arm on it for the kick down cable. The manual tranny and turbo 400 carbs were different. Like in this link.
http://www.crankshaftcoalition.com/w...4MV_carburetor

[mw67rs]

Thanks. Looks like mine is set up for an automatic so I am good. Thanks for the link. I have never rebuilt a Rochester only Holleys so a how to is a big help.

[geezer#99]

One more. Not exactly the same but always good info.
http://www.vetteprojects.com/kstyer/quadrajet.htm

[enaberif]

Originally Posted by lindstromjd

The carbs set up for a manual transmission have different accelerator plunger specs than those for automatics. You'll over-fuel and bog down on acceleration until the engine catches back up with the fuel delivery. I would try to find one for an automatic and rebuild it. There are a lot more of them out there than there are ones for manual trucks. And they're not hard to rebuild, just clean the hell out of everything you can with car cleaner and a toothbrush and pay really, really close attention to your measurements and specs. Be anal about them or you won't run right.

The only real difference between an automatic and manual quadrajet is the linkage for the gas pedal.

On a manual transmission style carb there is no spot to allow the hookup for the transmission cable where on the automatic there is. Internal parts are identical between manual and automatic carbs.