Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 187109 found under Guide Valve Stem by Dresser Industries Inc. The National Stock Number assigned to this part is 2805005691397, 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 187109.