Well my tame local engine tuner deals with REC , and is to ring Paul today or tomorrow . He felt the exhausts are restrictive , when you consider the sharp Short Side Radius , even with porting , it will help the engine breath out . I need to change my guides and valves anyway , so I'm gonna go for the 40/35 combo . With either carbs or TBs , newman fast road cam ,mild skim of head to keep the compression high , and I've a nice 4-2-1 Ex mani. Probably lose the dizzy for either an Omex or DTA ignition too. I'll be hoping for a nice torquey 135-140 bhp .