Gota ask...why load...anything to it's maximum capacity and use it on roads? For one of these it will not only handle and ride terrible but also tax the little 800 into a much shorter lifespan. Or was that just a figure of speech. For more road use I would go with C1 and 24 gram Dr Pulley sliders. That's it. You can always go to B2 if needed later. You will also find heavy road use will cause the belt temps to increase so I would also put a temp gauge on it and an Aux blower so you can help it only when needed. Some of my highest belt temps were on the road traveling at 40mph or so...and I'm not loaded-up.
Thank you for the suggestions!
Eventually I hope to go cross country overlanding, avoiding pavement as much as possible - Backroads Discovery Routes, Trans America Trail, Great Western Trail, Arizona Peace Trail, etc. I chose the Zforce 800 so I can get to more remote places with a 50" machine. There is a facebook group called " Loop Around the USA in a SxS ". They started in Arizona 17 days ago, currently in Michigan.
I plan on snorkeling all the intakes, with blower on belt air as you suggested.
I made a spreadsheet to calculate total weight of everything - aftermarket accessories (windshield, bumpers & stuff), gear, food, extra fuel / water, empty container weights for everything, and driver. Currently I'm 67lbs over max weight.