1966 Holley gasket question.

[Michael K.]

I removed the Holley 4 barrel from my 327 300hp for a repair. In addition to the gasket that goes between the carb and intake manifold there is an aluminum plate gasket. Is this something someone added on in order to dissipate heat to prevent the fuel from perculating in the bowl, or was this installed when the car was built at the factory for the same purpose? Is this an essential piece that I should put back on or will a new felt gasket between the carb and manifold suffice? Thanks. Michael Kalogridis

[Joe L.]

Re: 1966 Holley gasket question.

I removed the Holley 4 barrel from my 327 300hp for a repair. In addition to the gasket that goes between the carb and intake manifold there is an aluminum plate gasket. Is this something someone added on in order to dissipate heat to prevent the fuel from perculating in the bowl, or was this installed when the car was built at the factory for the same purpose? Is this an essential piece that I should put back on or will a new felt gasket between the carb and manifold suffice? Thanks. Michael Kalogridis

Michael-------

If it's really an ALUMINUM plate, it's not original. However, if it's actually a thin STAINLESS STEEL plate, it's original. If your car has an active "heat slot" (the long, narrow slot at the front of the manifold's carburetor flange), then this plate is absolutely critical. It must be installed on top of the gasket (i.e. between the carburetor and gasket).

However, I recommend disabling the "heat slot". This can be done by installing cup-shaped, drive plugs in the holes on either end of the slot or drilling and tapping the holes for internal hex head pipe plugs. This "heat slot" system is the greatest "killer of carburetors" ever devised. GM completely abandoned it for 1970 and beyond.

[Michael K.]

Re: 1966 Holley gasket question.

Great, thanks very much Joe. mk

[Dave B.]

Re: 1966 Holley gasket question.

Joe,Do you know if those Stainless Steel plates are available?Dave

[Timothy B.]

Re: 1966 Holley gasket question.

Dave, I know for a fact they are available in reproduction, not sure about GM.

[Joe L.]

Re: 1966 Holley gasket question.

Joe,Do you know if those Stainless Steel plates are available?Dave

Dave------


The GM baffle is long-since discontinued. However, they are available in reproduction. I don't think anyone will know the difference.

However, if the heat slot is disabled, which I highly recommend, the baffle is really no longer necessary. Of course, I'd still install one if for no other reason than maintaining the correct overall dimension between the carb and manifold (and on which the stock choke rod length is based).