The stock Corvair exhaust pipe stubs that are pressewd into the cylinders are too small and restrictive for this engine. New stubs were made from 1.25" OD, 0.049" wall thickness SS 304 tubing. A conical ring was formed using a Magnificent Machine forming die to fit near the outlet end and welded in place to give a sealing surface for the exhaust gasket. A tool had to be made to constrict the stub pipe for clearance where it passes by the pushrod tube.