CT 1970 Quadrajet 7040509 600cfm - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Tripmiester · 12-17-2018, 09:01 PM

Have a nice 600 cfm Quadrajet from 1970 California only manual transmission
$125 shipped
Came off a running truck 10 years ago, probably needs a rebuild it has been in a plastic bag in dry storage.

Tripmiester · 12-18-2018, 07:38 AM

ttt

Tripmiester · 12-19-2018, 07:28 AM

Bump

**special-K** · 12-19-2018, 09:34 AM

I guess I'm ignorant off these. Could you explain what makes this one special? Are 600cfm Q-jets rare or uncommon?

Tripmiester · 12-31-2018, 09:17 PM

ttt

**Oddfire** · 01-01-2019, 07:30 AM

Quadrajets only came in 3 sizes: 750, 800, & 840. 750s were used exclusively on all Chevrolets. 800s were used on later model Buick Olds Pontiac & Cadillacs. The 840s were a special Hi-Perf breed used only on Pontiac SD 455s for 1 year...1970. The 750s were also put into service on some 6 cyl applications made possible by using smaller Idle tubes & idle down channel & restricting the opening of the secondary airflaps. The 0509 carb you have listed originally came on a 70 truck with a 396 w/ manual trans & destined for Cali. Didn't mean to write a book or cause any problems in this thread but I've been using these carbs for years & thought it necessary to provide this information.

Tripmiester · 01-01-2019, 09:49 AM

Oddfire,
Thanks for the info, so is this a 600 CFM?
Here is a reference sheet but I don’t see a CFM identification column.

Thanks
Trip

**Oddfire** · 01-01-2019, 03:03 PM

No...the airflow of that carb is 750cfm the factory controlled the metering for various engines by drilling the idle air bleeds, down restrictors and also the main jet/ metering rod combos. No matter what you've heard...there's no such thing as a 600 or 650 qjet. jamie

**Oddfire** · 01-01-2019, 03:14 PM

7040509 CHEV 70 TRUCK 396 CALIF 78 49 7036019 BG 2.8926 4.2474

This is right off of Lars sight. The following info is what all these numbers mean:

Carb # Application Main Jet Main Rod Spring Sec. Rod Jet Area Jet Area

This does not however give the cfm ratings...that's just a given

Tripmiester · 01-01-2019, 03:20 PM

Oddfire,
Thanks for the expert info!

12-17-2018, 09:01 PM	#1
Tripmiester Registered User Join Date: Jul 2018 Location: Bethany Connecticut Posts: 360	1970 Quadrajet 7040509 600cfm Have a nice 600 cfm Quadrajet from 1970 California only manual transmission $125 shipped Came off a running truck 10 years ago, probably needs a rebuild it has been in a plastic bag in dry storage. Attached Images

12-18-2018, 07:38 AM	#2
Tripmiester Registered User Join Date: Jul 2018 Location: Bethany Connecticut Posts: 360	Re: 1970 Quadrajet 7040509 600cfm ttt

12-19-2018, 07:28 AM	#3
Tripmiester Registered User Join Date: Jul 2018 Location: Bethany Connecticut Posts: 360	Re: 1970 Quadrajet 7040509 600cfm Bump

12-19-2018, 09:34 AM	#4
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,863	Re: 1970 Quadrajet 7040509 600cfm I guess I'm ignorant off these. Could you explain what makes this one special? Are 600cfm Q-jets rare or uncommon? __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

12-31-2018, 09:17 PM	#5
Tripmiester Registered User Join Date: Jul 2018 Location: Bethany Connecticut Posts: 360	Re: 1970 Quadrajet 7040509 600cfm ttt

01-01-2019, 07:30 AM	#6
Oddfire Senior Member Join Date: Jan 2013 Location: Front Royal, Va Posts: 689	Re: 1970 Quadrajet 7040509 600cfm Quadrajets only came in 3 sizes: 750, 800, & 840. 750s were used exclusively on all Chevrolets. 800s were used on later model Buick Olds Pontiac & Cadillacs. The 840s were a special Hi-Perf breed used only on Pontiac SD 455s for 1 year...1970. The 750s were also put into service on some 6 cyl applications made possible by using smaller Idle tubes & idle down channel & restricting the opening of the secondary airflaps. The 0509 carb you have listed originally came on a 70 truck with a 396 w/ manual trans & destined for Cali. Didn't mean to write a book or cause any problems in this thread but I've been using these carbs for years & thought it necessary to provide this information.

01-01-2019, 09:49 AM	#7
Tripmiester Registered User Join Date: Jul 2018 Location: Bethany Connecticut Posts: 360	Re: 1970 Quadrajet 7040509 600cfm Oddfire, Thanks for the info, so is this a 600 CFM? Here is a reference sheet but I don’t see a CFM identification column. Thanks Trip Attached Images

01-01-2019, 03:03 PM	#8
Oddfire Senior Member Join Date: Jan 2013 Location: Front Royal, Va Posts: 689	Re: 1970 Quadrajet 7040509 600cfm No...the airflow of that carb is 750cfm the factory controlled the metering for various engines by drilling the idle air bleeds, down restrictors and also the main jet/ metering rod combos. No matter what you've heard...there's no such thing as a 600 or 650 qjet. jamie

01-01-2019, 03:14 PM	#9
Oddfire Senior Member Join Date: Jan 2013 Location: Front Royal, Va Posts: 689	Re: 1970 Quadrajet 7040509 600cfm 7040509 CHEV 70 TRUCK 396 CALIF 78 49 7036019 BG 2.8926 4.2474 This is right off of Lars sight. The following info is what all these numbers mean: Carb # Application Main Jet Main Rod Spring Sec. Rod Jet Area Jet Area This does not however give the cfm ratings...that's just a given

01-01-2019, 03:20 PM	#10
Tripmiester Registered User Join Date: Jul 2018 Location: Bethany Connecticut Posts: 360	Re: 1970 Quadrajet 7040509 600cfm Oddfire, Thanks for the expert info!



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