Hey I have some what of a similer set up on my bike, my buddies is probably closer to yours then mine. I had my bike ported by Cascade and I have a 4mil with the long rod crank. I had 50hp on Cascade's dyno before I did the port and long rod stroker crank and I had FMF pipes and stock carbs. I was running a +4" then and 9 paddle extremes and could hardly ever get the front end off the ground when riding dunes except over bumps and then gas'n it. Now I kept the +4" with the port, new carb, crank, first over bore, and Paul Turner pipes and the +4" was good with the 9 paddles. I liked it very much could I get the front end up a hole lot more easy. I then put the 10 paddles on and now I can almost get the front to come up at will I like this set up better and I can still do the hill climbs just fine. Cascade recomends the +8" so the front end does not come up at all or very little. Cascade is also running the 22" to 25" tall paddle tires mine are only 20". They told me +6" to the +8" too. My +4" is fun to ride, I am running stock gearing, was running 13 tooth on the front when I did not have the engine mods. My buddy Has the same set up with t5's, 28mm PWK's, 2nd over pistons and he likes the +4" too. We both have about 165 psi kicking compresen(19cc domes) and are running 104 Octane. Hope that helps. Can you tell I just like talking about my shee.