Carb for my 318

I'm not an expert on any of this, but regarding "Holley Remanufactured" ThermQuads, Summit Racing has some of them for sale at,

http://www.summitracing.com/search/?keyword=Holley Remanufacured Carburetors Thermoquad&dds=1

This is what they mean by "Holley remanufactured carburetors":

"Holley remanufactured carburetors--which include other brands, such as Carter and Rochester--are rebuilt to the same high standards that Holley applies to its new carbs. Every one undergoes a very stringent remanufacturing process that virtually guarantees its performance will be equal to the factory product. All-new hoses, gaskets, diaphragms, fuel inlet valves, O-rings, and accelerator-pump components are used, and any reused components are thoroughly cleaned. After they're assembled, they receive numerous detailed quality and performance checks (including flow testing) before they're released to the market, to ensure reliability and longevity."

So apparently they are just rebuilt carburetors.