P/N: ES-180HP Price: $325.00 each Eligible On: PA-18 Series Aircraft STC: N/A FAA/PMA: N/A Material: Stainless Steel Purpose: Modifies both front and rear stacks to fit 0-360 engines and comply with 180 HP STC's. Misc. Information: Welding work is performed in our repair station. Please call us to schedule this service.