Insulating Against Heat on the Carb

I've cured similar hot carb issues in the past by both making and installing a semi-ridged, sheet-aluminum plate to shield and dissipate heat transfer from the engine to the carb, and installing a 1/2" phenolic spacer on top of that. Using this combination requires 3 gaskets and longer studs. Be sure that the aluminum plate does not interfere with any linkages or throttle blades etc.. Also, depending on your intake design, you can use an open plenum or 4-hole style spacer. I sourced a one foot by one foot piece of aluminum sheeting from my local hardware store and cut it to fit. It was pretty thin, but still thick enough to be somewhat rigid.

Another successful addition I made was to use a gas filter with the return nipple to circulate the fuel back to the tank. I had to add the return line to the back of the car and a fitting on the sending unit to make this happen.

Having your ignition timing properly tuned helps too.