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It might, but you will need to change the manifold too, as a Holley square bore wont bolt to your stock intake. ..........and adapters are not worth their weight.


Don't rule out the Quad....It can be a very good carb.....just needs a bit of tuning.
 

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I ran them both so I am not biased but either carb was used in a production vehicle so that through my old theory out the window about the holley only being good for WOT. However, I took a QJet off a 78 Cadillac 425 smogger boat (I like Cadillacs too), never changed the mains but tuned the primaries with the power valve rods, power valve stop, and the power valve spring on the primary side and air door spring tension (made my own spring tensioner for it too), rod hanger, and secondary rods and never looked back. Its an awesome carb to play with, just have some patience and hold your jaw a certain way. I was also glad to know that I never had to worry about a diagrams ripping or blowing out. Oh yea, double check throttle shaft bore wear and welch/plugged holes in the QJet. A little epoxy goes a long ways.

I forgot, I put that carb on a built 360 Mopar engine, ran terrific!
 

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Q-Jet for me all the way. That is all I use. Most dudes don't know that the q-jet is almost an auto carb, it will adjust to almost any vacuum created by the engine and perform flawlessly over a wide range engine demands. As I said the q-jet is the only carb you can install and get years and years of flawless service.
 

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+1 for the Qjet. The tests have been done, no other carb, factory or aftermarket is more accurate at metering than a Qjet.... properly set up of course. Small primaries for killer throttle response, typically less fuel consumption than other carbs.

I'm convinced that the only reason NOT to use a Qjet on the street or street/strip application is because the user is afraid of Qjets or think they are tough to tune. Otherwise I think they are a far superior carb as far as metering goes. Don't get me wrong... all the major carbs you find on engines are fine pieces and can be tuned for identical power and drivability, but if you can get better throttle response and mileage, why not ? :)
 

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Rat Rod said:
Q-Jet for me all the way. That is all I use. Most dudes don't know that the q-jet is almost an auto carb, it will adjust to almost any vacuum created by the engine and perform flawlessly over a wide range engine demands. As I said the q-jet is the only carb you can install and get years and years of flawless service.
Yep. The same basic 750-800 cfm Qjet was installed on 231 V6 buicks, and 135-hp Olds 307s, all the way up to the 455s and Caddy 500s.
 

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curtis73 said:
+1 for the Qjet. The tests have been done, no other carb, factory or aftermarket is more accurate at metering than a Qjet.... properly set up of course. Small primaries for killer throttle response, typically less fuel consumption than other carbs.

I'm convinced that the only reason NOT to use a Qjet on the street or street/strip application is because the user is afraid of Qjets or think they are tough to tune. Otherwise I think they are a far superior carb as far as metering goes. Don't get me wrong... all the major carbs you find on engines are fine pieces and can be tuned for identical power and drivability, but if you can get better throttle response and mileage, why not ? :)
When you put it in that sense Curtis, some other brand carbs can come close. Mainly the ones with the metering rods like Carter AFB, AVS, and the "THERMOQUADDDDDDDDD" (My personal favorite after the QJet of course). If I am not mistaken, Rochester provided 3 taper rods for the primaries on "some" QJets, now can you imagine 3 different fuel curves and specific vacuum points from a carburetor? Up to 2 tapers for the secondaries! How the tar can you possibly go wrong with this carb?!

Yes, it blows my mind when thinking about it because Oldsmobile carbed the 307 right up until its end when electronic metering was the norm. Anyone afraid of that electronic QJet is afraid of their own shadow as far as I am concerned. The crazy thing is slightly tunable on the primary side. The secondary side is just like any other QJet after you do a little filing to the air door stop.

Ok, I will get off my soap box because I didn't even scrape the surface yet and I know some of you know how much I can ramble on. Next person please!
 

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If you aren't afraid to try new things then Q-Jet all the way. There are easier carbs to work on but they also fall short of the tunability of the Q-Jet. There are some good Q-Jet manuals out there and while it's a little long in the tooth now ( but then so is the Q-Jet ) the first one you should buy is Doug Roe's "Rochester Carburetors". Don't even lay a finger on a Q-Jet without one. There are some new books out but I haven't added them to my library....... yet.

The 600 Holley is a good carb and will perform well but it doesn't have the fuel economy and performance potential of the Q-Jet. That's the other nice thing about the Q-Jet it is capable of good mileage AND strong performance. If I see one laying under somebody's bench that looks like it is on it's way to the trash I'm not shy about asking if I can have it. Even if the carb is trashed I can always use more metering rods, hangers and jets.

Getting one dialed in can be a long process, especially the first one, but once you get it there it is worth every second. :thumbup:

Even if you decide to put the Holley on it now don't ditch that Q-Jet. You're probably going to want to give it a try later on.
 
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