well, are you running the stock tires? THey are very heavy. Getting some Proline masher 2000's or some other lighter 2.2 rubbers will help.
What pinion gears are you running? Stock ones or steel ones?

A better clutch helps too. You can get a savage 3 shoe clutch and flywheel on ebay for a couple bucks. Then Pull one of hte pins out of the savage flywheel and arange the pins on the Cen flywheel in a triangle, then you can install the 3 clutch shoes and springs for a better grab.
then, you can get some nova racing alum shoes (or similar) and put them there instead of the soft shoes. The nova ones have little weights that screw in to adjust the clutch.