I know I've only had my Argo for about 6 weeks but I would really like to put a more powerful one in. My machine is a 98 Vanguard 6x6 with the Vanguard 16hp twin cam motor. The reason is not for speed but where I ride there's a lot of hills and my machine has a real hard time with them. What's the best motor that will fit in the place of the one I have now? I'm not looking for anything crazy just a little more power.