Hesitation issues - need help

You're on the right track, but the stalling surging and back firing got me curious. I have to wonder if your timing is really where you think it is. If the balancer is starting to slip, your marks are off and can only be verified by a piston stop and knowing where top dead center is. The stalling and surging has me wondering if there isn't crap getting stuck in your float needle and floating around in the bowls. I have heard of the chrome on the inside of carb bowls flaking off and plugging jets. Surging can also happen if the gas tank is not vented. Maybe some of the gurus will chime in with some other suggestions. For what it's worth, I run the same xe268h cam in my 350 and it's initial and total is 18/34.