Just make sure the mount allows the width of the washer. I had a Nylon mount fail when (it appeared) the washer pushed hard against the reenforcing web above the flat and deformed it, eventually causing it to fail. As I remember I also had a problem getting the engine to seat flush on the mount flats and probably put excessive torque on it when tightening the bolts. It was on a Stik style model and easy to spot (three bolts still held). Since then I file a flat on the washers with a Dremel so they have clearance and the engines seat as they should.