are they the same size front and back?

i was looking at 26x11x12 rear and 26x9x12 fronts..mudlite radials(xtr) i think

any idea of the true weight difference

 

They have the specs on the tires at ITP's website. The difference between the 26-11-r12 XTR and the 26-12-12 Mudlite is 5 lbs. each. It shouldn't be a problem for your 800.

 

whats the difference in weight from the stock

 

i know itps a great brand and all but before you go off and buy a set look at http://www.completewheelsource.com/2007/atv.html their called motorsport alloy wheels and i think they look alot better than the itp

 

So you haven't noticed any difference in the visco loc system. I heard bigger tires really makes a mess of that system.

 

The visco lok is a simple mechanical system. As long as both front tires are the same size, it works fine.

The weight difference between stock and the c7's with the mudlites is at least 5 lbs. per corner. The stock stuff is feather weight. If you go to XTR's your at about 10 lbs. per corner. Not a problem for the 800 or even the 650, but for the 400 it will kill it.