You should think about to buy a good clutch too. There are very good ones on the market. S&S or MMW. So if you change your primary to 23/65 or 22/65 you´re going to be happy with the engine. For me too, the M1X is the better Cylinder. It has some nice features,for example the Exhaust Plug from Schall&Rauch with the Viton Ring... It also has more potential and if you are not going to crazy with milling, it is a very reliable Cylinder with no disadvantage.