I have a 34T on one of my bikes and a 36T on another one, with a good free flowing exhaust, a properly tuned carb. and a thinner head gasket or just sand a few thousands oof the head and both of these work great for me, I have hills I have to climb all around here and I never have to peddle on any of them, I top the hills still running 20+ MPH, 25-27mph on most of them, I weigh 200lbs.
I hade the stock muffler on one bike after installing the 34T sprocket and it would barely pull me on the bike, it was a real dawg.......until I put a SBP expansion pipe on it and then with only that one mod. it pulled the 34T just fine, I say just get a good free flowing exhaust even if you dont use an expansion pipe and it will make a world of difference in my experience.
Peace