Ok Guys, I dont have a clue as to why the mechanic called it a corvette modification. The idea is simple, the rubber washer that goes between the intake manifold and the water pump is prone to leak. so you put a softplug in the intake and the manifold and no you dont need the bolt. Issue now becomes how do you get water into the mainfold. rather simple, you drill a hole thru the edge of the thermostat. useing a 1/8th" drill bit. We did this on bb block chevys for years and did away with the hose from water pump to the intake. Drilling the hole is the key to susccess. Kevin
