I am running pretty much the same fuel you are and it could be that the high oil content in your engine is bogging it down. When you lean it out is it up around 250? and does it get bogged down at idle or when you are running it? If it is only at idle your low end needle (if equiped) needs to be leaned out. If its not equiped you could open up your idle screw a tiny bit. Be careful to monitor temps at idle so the engine doesn't overheat. It is probably not shifting because of a slightly off tune engine and a mis adjusted shifter. There should be some sort of adjustment on the transmission to change what RPM it shifts at. Good luck with it.