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I'm starting to pull parts off of my engine for it will need to be pulled for a rebuild and paint. Today I pulled off the carb, basically to see what I have and found it is a QuadraJet #7045562. From what I can tell it is from 75 engine (based of internet decoding websites).

The 455 was pulled long ago before I got the car, I believe the motor in it now is a 350, as what I was told.

My question is (for you motor guys) what do you know about these carbs and would this carb be good for a 400 or 455 motor, which is what I'm heading for down the road.

Thank you in advance for the responses. :cheers
 

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I'm starting to pull parts off of my engine for it will need to be pulled for a rebuild and paint. Today I pulled off the carb, basically to see what I have and found it is a QuadraJet #7045562. From what I can tell it is from 75 engine (based of internet decoding websites).

The 455 was pulled long ago before I got the car, I believe the motor in it now is a 350, as what I was told.

My question is (for you motor guys) what do you know about these carbs and would this carb be good for a 400 or 455 motor, which is what I'm heading for down the road.

Thank you in advance for the responses. :cheers
It's indeed an early model year 1975 (8-digit code starting with "7" and "45" in posiitons 3-4), California Quadrajet ("5" in position 5), from a Pontiac ("6" in position 7) with an automatic transmission ("2" in position 8).

It'll be a decent carb with a rated flow capacity of 750 cfm. With proper perparation it'll run nicely on "most" 400's and also on mild to moderate 455's.

There were a few Qjets "back in the day" that were 800 cfm models, such as the one that originally came on the 455SD. I hear they're very hard to find and very expensive now.

A really good reference book to get is the one by Cliff Ruggles, "How to Rebuild and Modify Rochester Quadrajet Carburetors", available on his web site and also most popular book stores.

Bear
 

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Interesting. According to HPP Dec 2006, that carb is a M4M. All M4M carbs flowed 800 cfm. They started producing them in '75. As mentioned, SD455s 4M flowed 800cfms. They even had some 4Ms flowing 828cfms on the '71 455 HOs.
 

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Upon firing the motor up after its reinstall of it and my Q-Jet a bad fuel leak was discovered at the fuel inlet. Many Q-Jets now have an insert in the inlet or heli coils as the threads over the years are shot. A possible issue thought was fuel was leaking between the insert itself and the carb's body. Was told if thats the case the carb must be dissassembled the insert pressed out a new piece CNC machined and inserted. I was told 2-300 range.. Eghads.

I went looking a better alternative and found an outfit in New Jersey that rebuilds and sells Rochester's. I could have gotten a rebuilt one ready to go (correct carb for the car) with a warranty for just over 500. Thought was to sell mine to offset this cost. I figured I could get a "new" old Rochester for 200 when all said and done.

At any rate I was lucky it was just a washer that needed replaced, the carb was pressure tested and all is well.

The link here is to this site with Carb numbers for anyone to reference or are looking for "new" Rochester: Custom Rebuilt Carburetors - Carburetors
 

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I have a 7026200 E6 from the side of the carb on a stamped tag pressed int to the round casting. Looks to be a 1966 396/325hp automatic carb with smog. Is this right and what is the cfm on it. On the back is raised numbers in a circle and read 7032720 on the main body, which would seem to be 67. So I am woundering if it is late 66 or a reman.

Mine is close to this one on this link, but not exact as the linkage is a bit different. It does have a bracket similar to the one in this post, for what would look like the 400turbo kick down, But mine does not have the post for the throttle, only holes.

mystery '67 quadrajet? (need ID help) - Chevelle Tech

I wounder if it is big car chevy like Impala ss 396 with 400turbo or Caprice. They did have 66 ss396/325 400turbo Chevelles but are a bit rare not as much as 427 cars but most cars then had power-glide's or 300 turbine's for auto's.

 

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Yea that is what I came up with also. Google is my buddy but isn't as knowledgeable as real people like the ones here. I am wondering about the CFM on it really. Nothing comes up on the google.
 

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Interesting. According to HPP Dec 2006, that carb is a M4M. All M4M carbs flowed 800 cfm. They started producing them in '75. As mentioned, SD455s 4M flowed 800cfms. They even had some 4Ms flowing 828cfms on the '71 455 HOs.
Well, strip my gears and call me shiftless... :D I had just always "assumed" that all of them were 750's except for the few that were 800's. You might fire off an email to Cliff (get the address through his web site, or use his contact page here: Cliffs High Performance Quadrajets :: Qjet Carburetor Rebuilding, Bushing Kits, Quadrajet Rebuild Kits and Parts ), send him the number and just ask him what it is. He'll know for sure.

Bear
 

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The Rochester is very good for a hot street motor, but if your performance expectations are very high, then something like an 850 Barry Grant or Holley, etc. would probably give a little better WOT racing performance.
I, too, had inlet thread issues like GTO JUDGE mentioned a couple hours ago. So make sure they're in excellent condition.
I used a book by Doug Roe. Rochester Carburetors 1986 HP Books, Inc. ISBN 0-89586-301-4. Lib. of Cong. cat. # 86-81204. Good luck.
 

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Discussion Starter #10
Thank you for recommendation Bear. I ordered Cliff's book. Can't wait to get it.

Still not sure if I'll rebuild the 350 (maybe stroke it) or buy a 400 block, but I excited about rebuilding the carb.
 
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