I dont know exactly what your timing is but I think you need to recheck that. .012 is a little narrow. I think stock is .016. (changing point gap changes timing) It may not sound like much but timing is a huge deal on any engine. set your points and timing to stock settings using the stock procedure and then try it out. The stock setting is always a good starting point. I have run the exact setup as you and was running a 95 main jet, with stock timing with excellent results. I am in nebraska with faily high humidity and about 1800 ft in altitude. good luck