'66 350HP H2O PUMP DATE

[Rob A.]

Although I'm familiar with the "six month rule", realistically, would a '66 350HP engine stamped early June be more likely to have had a ...326 H2O pump dated February or May?

[John H.]

Re: '66 350HP H2O PUMP DATE

May, most likely. Those pump housings were cast at Saginaw and shipped (with all the other castings) to Flint Engine, where they were machined and assembled as finished pumps, then installed on engines. Flint made about 5500-6000 water pumps a day, and it's unlikely they'd have many February castings lying around in June.