Scooby,
You are correct it is a cast cylinder however there is a large flat on one side that has been milled, if that catches your eye with a quick glance the cylinder would appear to be billet.OK quick run down on the mods:started with 03 baja with vortex cdi, carb mount K&N, MBRP pipe(turd), 15 tooth front sprocket, 22x10x10 paddle hauler extremes. New additions: 04 snorkle tube with K&N no box,TM 45 carb with pump activated, ported intake, full ported head with + 1mm intake and exhaust valves, shim under bucket springs, web 109/110 cams,730 cylinder with 14:1 piston,+ 60% clutch springs,LTE exhaust, + 4" TBR swingarm.Still to come new rear shock.Does'nt seem like much in a list but the checkbook took a mighty blow.Ron