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Hey guys, been readin on this forum for a while but never posted so here we go. I have 74 deville that I swapped a 68 472 into. I need a carb for it and I’m having a hard time. I see the intake manifold has some kind of passage at the front of the carb maybe emissions? I’ll attach a pic of the same intake I have, just want to make sure I get the right carb! Thanks in advance , bryson
571832
 

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Welcome to CF CaddyDaddy!

The passage you see is the exhaust gas heat passage which is routed right under the carb throttle plate. Pretty much any Q-Jet will work as far as that passage is concerned, as far as I know.
However, I would look for 1 of 8 particular Q-jets that are original equipment for the 68 472. They are part numbers 7028230,31,34-39. There are slightly different settings listed for them in my Motor manual, but that will get you close. You also need to match the style of choke.

The reason is that other years or models do not have the same calibrations that your engine needs.

By the way, you say you need a carb. Do you not have the original from the 472? Rebuilding that one is the much preferred way to go.

Bjc789
 

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-Administrator- 2002.5 F55 STS 2014 FWD Explorer
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Yep, that's part of the exhaust gas heater passaging - "heat riser'. The small cavity above the carb base is the heat sink for the old choke coil spring. Rebuild the carb with the newer electric choke kit.

If you run into trouble rebuilding your original QJ find the Doug Roe HP book "Rochester carburetors" on Amazon. Everything you ever wanted to know about QJs.

Or talk to the guys at www.allcarbs.com
 

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That style intake manifold MUST have a heat shield between carb and manifold. No heat shield = damaged carburetor and it'll run crappy because of all the exhaust gas leaking into the fuel/air mix.

You'd put the HIGH-HEAT-RESISTANT gasket on top of the manifold, place the heat shield on top of the gasket, then place the carb on top of the heat shield.
 

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Discussion Starter #5
I’m a little late on replying but I ended up with a nice reman carb and the correct gaskets. Runs like a top! Thanks for the advice guys
 
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