Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 58321D found under Valve Poppet Engine by Hercules Engine Co Inc. The National Stock Number assigned to this part is 2805002719069, and the Federal Supply Class is 2805 Gasoline Reciprocating Engines Except Aircraft And Components. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 58321D.