2 different Q-jet gaskets?

[85 Shortbox]

I recently swapped to rebuilt q-jet and I used a gasket between the manifold and carb the had a gap in front of the primaries in between them. Now I have a buddy who just rebuilt his 350 and saw the gasket he was putting on in the same place and it had material covering in the place mine didn't, both were new (not old trimmed gaskets) so what is the difference and why? Thanks.

 

[dyeager535]

Not sure what GM was thinking when they did that, but yes, there are different intake to carb gaskets. Actually more than just two different gaskets, as there are ones that have the secondaries joined and divided.

One of the reasons for different gaskets are the vacuum passageways that were added or removed during the Q-jets lifespan of 1965-1990.

 

[chevyracing]

I think one is EGR and the other is non EGR type.

John

 

[85 Shortbox]

So how do I tell which to use?

 

[dyeager535]

Usually you just use the style that you removed. Short of that, I'm at a loss. If the rebuild kit comes with two gaskets, it won't help you any, but I don't recall if all rebuild kits come with 2 different carb to intake gaskets or not. You buy those by the stamped in ID number, so that SHOULD get you the right gasket if there is only one per kit.

If you've got a local carb shop, they might be able to look that info up for you as well.