you should measure the thickness of the old one if you have it and get one a little thicker than that make sure to check the squish after reasembly min clearance is 40 thousanths base gaskets usually can ge ordered in different thicknesses good luck.Rotax779 said:Hi!! I have 94 Mach780. Does anyone know the thickness of the BaseGasket on this Model?? I bought a new head that has been cut down 40 thousands reverse cut by Crankshop. Can anyone help get a basegasket to use with this head?