Quadrajet carb

thomas g. warner

New member
Mar 24, 1998
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I am not aware that olds 455 engines came with anything but rochester
Quadrajet carburetors.If it has a holly installed now, than someone replaced
the original quadrajet with it. Summit, JEGS, JC Whitney and others have the
complete range of parts for the Holly. I would keep it and use it if you
know how to check it and tune it for the 455.

Here is some information I got from somewhere on the web sometime last year
and believe it to be accurate FOR THE ROCHESTER QUADRAJET.

This information is a composite of a 1991 Caughlin Coach Talk, Doug Roe's
book and the big Rochester parts book.
Year Carb No. Primary Jet Primary Rod Secondary Rod Sec.
Rod Hanger
73-74 7043254 70 50D CJ V
75-76 Fed 7045254 70 50D CJ V
75-76 CA 7045554 68 ` 50D CJ V
77 403 17057254 67 7043541 CK V
78 17057559(CA)
17058254 67 7043541 CV V
The Carburetor Numbers are on the left side, in front of the boss that
runs vertical beside the secondaries. Probably unreadable with the carb
on the vehicle unless you use a magnifying mirror. There are other
subtle differences, such as the power spring (4-8 in hg)
hot unloader (not present) for the 455 and secondary air valve setting
that are unique to the motorhome.
It is important to make sure you have no vacuum leaks and that you have
the correct line connections. Both problems that I have seen and
experienced. The addition of a vacuum gage and an air/ fuel ratio meter
are helpful in keeping track of your carb performance. An air/fuel
meter is available from Summit, Edlebrock, Westach and probably others,
or you can make one from a three wire O2 sensor and a volt meter. 1
volt = 14.7 A/F.

>Have '73 w/455, carb has sticker where ID plate should be: "factory
>remanufactured by Holley"......How to know model of carb & rebuild kit to
>use????
>Lanier
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach
"The beautiful Mohawk Vally"
 
I am not aware that holly remanufactures the rochester quadrajet either.
the parts are not interchangeable. If it is a Rochester it will have the
name molded in the side.

>In a message dated 6/14/99 3:38:46 PM Central Daylight Time, warner
>writes:
>
> I am not aware that olds 455 engines came with anything but rochester
> Quadrajet carburetors.If it has a holly installed now, than someone replaced
> the original quadrajet with it. >>
>It's a Rochester Quadrajet, just with a paper sticker on it that says
>"remanufactured by Holley".
>Holley makes a replacement for the QJ - Model 4175 @ 600cfm; Edelbrock now
>makes its own QJ with figures from 600cfm - 795cfm but engine size quoted
>goes only to 454cid (may be a misprint).
>Summit has 'em all.
>Lanier
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach
"The beautiful Mohawk Vally"