Is this ignitor suitable for the Goodman GMS8 series furnaces?

Yes, this ignitor will work in a GMS8 series furnace. The parts manual for the furnace may not list the "S" at the end of the ignitor's SKU, but for all intents and purposes "20165703S" is the same as "20165703".

If you have any further questions, please call us and we will be happy to assist you.