69 350/350 intake to carb gasket

[james Kekeisen]

I have installed a stock cast iron intake manifold on my 69 350/350 and have rebuilt the Q-jet carb with much help from this board.

My question: What is the appropriate carb to intake gasket. A thick one (3/8") with no individual bore holes (center of the gasket is wide open) came with the rebuild kit. I also have a new thin gasket that has the primary and secondary bore holes. I have plugged the heat transfer groove holes (in the intake manifold) per this boards advice.

Thanks, Jim

[Dennis D.]

Re: 69 350/350 intake to carb gasket

Should be thin gasket, 4 bore holes, slot in front for heat groove. I believe you should also have the steel baffle. same configuration as the gasket. Dr Rebuild's site shows the two. Good luck dennis

[Dennis D.]

Re: 69 350/350 intake to carb gasket

Should be thin gasket, 4 bore holes, slot in front for heat groove. I believe you should also have the steel baffle. same configuration as the gasket. Dr Rebuild's site shows the two. Good luck dennis

[james Kekeisen]

Re: 69 350/350 intake to carb gasket

Steel baffle? Is that necessary? A regular gasket paper gasket won't work?

Thanks, Jim

[james Kekeisen]

Re: 69 350/350 intake to carb gasket

Steel baffle? Is that necessary? A regular gasket paper gasket won't work?

Thanks, Jim

[Joe L.]

Re: 69 350/350 intake to carb gasket

James-----

The original gasket for your application was an asbestos-composition gasket with a steel core. It had the 2 large secondary holes and the 2 small primary holes. It was about 3/32" thick. This gasket was used in conjunction with a stainless steel heat baffle. The gasket was installed on top of the manifold first, then the heat baffle, and then the carburetor.

If you have plugged the carb heat heat groove in the front of the manifold, then you don't really need the heat baffle. However, if you have it, I'd still recommend installing it.

The thick insulator gasket was used on many 70+ applications. It is advantageous in that it will further insulate the carburetor from manifold heat and that's a good thing. Although not "correct" for your application you can use this gasket in place of the above-referenced. The only problem is that you will need to fabricate a new choke rod which goes bewteen the divorced choke thermostat and the carburetor to accomodate the extra thickness of the insulator gasket.

The original GM carb gasket for 68-69 with Q-Jet, GM #3884574, is discontinued. However, I believe that reproductions are available from Dr. Rebuild and others. The stainless steel baffle, GM #3884576, remains available for about $6.50 GM list

[Joe L.]

Re: 69 350/350 intake to carb gasket

James-----

The original gasket for your application was an asbestos-composition gasket with a steel core. It had the 2 large secondary holes and the 2 small primary holes. It was about 3/32" thick. This gasket was used in conjunction with a stainless steel heat baffle. The gasket was installed on top of the manifold first, then the heat baffle, and then the carburetor.

If you have plugged the carb heat heat groove in the front of the manifold, then you don't really need the heat baffle. However, if you have it, I'd still recommend installing it.

The thick insulator gasket was used on many 70+ applications. It is advantageous in that it will further insulate the carburetor from manifold heat and that's a good thing. Although not "correct" for your application you can use this gasket in place of the above-referenced. The only problem is that you will need to fabricate a new choke rod which goes bewteen the divorced choke thermostat and the carburetor to accomodate the extra thickness of the insulator gasket.

The original GM carb gasket for 68-69 with Q-Jet, GM #3884574, is discontinued. However, I believe that reproductions are available from Dr. Rebuild and others. The stainless steel baffle, GM #3884576, remains available for about $6.50 GM list