The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - New Q-Jet will not settle down to idle, it's driving me %$#%$#%$

**MJN** · 07-29-2020, 10:37 AM

The correct carb for your application should be stamped 70405XY
70= Rochester Carburetor
4= 1970-1975
0= 1970
5= California emissions
X= 0,1 or 2= Chevrolet
Y= transmission application Odd #'s 1,3,5,7,9 for manual trans, even #'s 0,2,4,6,8 for auto trans

Quadrajet Power LLC has some nice photos of a 7040502 that you can compare yours to.
https://quadrajetpower.com/chevrolet...rajet-7040502/

07-29-2020, 10:37 AM	#16
MJN Registered User Join Date: Feb 2000 Location: Maquoketa, Ia/ Orr, Mn Posts: 2,963	Re: New Q-Jet will not settle down to idle, it's driving me %$#%$#%$ The correct carb for your application should be stamped 70405XY 70= Rochester Carburetor 4= 1970-1975 0= 1970 5= California emissions X= 0,1 or 2= Chevrolet Y= transmission application Odd #'s 1,3,5,7,9 for manual trans, even #'s 0,2,4,6,8 for auto trans Quadrajet Power LLC has some nice photos of a 7040502 that you can compare yours to. https://quadrajetpower.com/chevrolet...rajet-7040502/ __________________ '51 South Bend Model "9A" '56 Chevy 3600 NAPCO '74 Chevy Cheyenne Super K20-restored on 37's '72 GMC Sierra Custom K2500- in progress '08 GMC Envoy Denali '12 GMC Sierra 2500HD Denali '17 GMC Yukon XL VCCA member #58596 http://www.nohrco.com