I'm no expert on Harley carbs but from my experience with British and Jap bikes I know they don't have an accelerator pump in them. If the Harley carbs don't use an accelerator pump then I think their use on a car or truck wouldn't be very compatable. If they do have accelerator pumps then I'd try to find out how much air they flow and if the floats & needles can withstand the pressure of being supplied by a fuel pump. Motorcycle carbs are generally gravity fed from the tank being above the carbs.
Ages ago the old sprint cars that ran Ford Model A or Model B 4 cylinder engines ran dual carbs and did not use the accelerator pumps but with the rpm of the engine at racing speeds and the relatively light weight of the little race cars the accelerator pumps weren't really needed.
Just a few things to ponder if you don't get a specific answer. It does sound like a great low cost option to Weber side drafts if it can be made to work.
