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I am just about to install the Quadrajet carb on my 68 327 Camaro and I need to know the correct sequence of the gaskets. I have a paper gasket and a steel type gasket. Firstly which one contacts the intake manifold? Secondly, the paper gasket has a cutout about 1/2'' wide running nearly the width of the gasket (just in front of the primaries) the original GM cast intake has the same cutout however, the steel gasket does not have this cutout is this correct? Thanks for any replies.
 

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Discussion Starter #3
Really I need 3 gaskets (2 paper and 1 steel). Maybe this explains why I had difficulty adjusting the air/fuel mixture screws. When adjusting them before there was little change in engine idle speed.
 

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The base gasket is not paper it is made the same as the exhaust man.gaskets with a steel mash in it.The way I install that;first steel then base gasket.The better way to do the hole thing is to install propane type intake gaskets the ones that block the exhaust ports to the intake.Then you can run paper style gaskets with out the steel plate.The holes that the steel plate covers are for winter driving which you will not do.(I hope) ;) Mr. :cool: Nick
 

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I just fought this issue for two days on my 68 350. I could not get my car to idle after replacing the carb at all and it acted like there was a major vacuum leak. I plugged all the vacuum ports and I used a propoane torch to look for leaks around the carb or manifold and found none. I then looked in the box of parts I had removed and saw that I had left the metal plate off. I placed the metal plate between the carb and gasket and problem solved.

I guess this confirms the old story: You should never have extra parts left over at the end of a job...
 

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The gasket that goes against the intake is heat resistant. It has wire mesh in it you put it on first then the steel plate then a paper gasket. Go to your local parts store and look in the Felpro catalog the stuff is avalible from them.
 

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No paper gasket - the heat-resistant thick gasket goes on first, then the metal baffle without the slot in it, then the carb. That slot in the intake lets hot exhaust crossover gases heat the carb base without contacting it directly, and has ruined (and rendered unrebuildable) more Q-Jets than you can count. A better long-term solution is to use 7/16" steel cap plugs (or freeze plugs, depending on what your parts guy calls them) and drive them into the holes at the end of the slots in the intake to keep exhaust gases out of that slot entirely; GM eliminated that slot entirely after 1969 due to all the carb failures it caused.
 

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The extreme localized heat from the exhaust gases warps the baseplate. It's also not coincidental that the intake slot was eliminated following the biggest carburetor recall in GM history when the bowl plugs started coming out of the bottom of Q-Jets and causing engine fires.
 
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