Driving my 30 Town Sedan, stock engine, carb and ignition, on a 130 mile club tour today over some hilly terrain. Reaching the top of a long climb the engine started to stumble, felt like the ignition was shorting out. On the down hill and level motor ran fine for a while but condition got worse on short hills and flat roads. Stopped and re gapped points which helped for a while but even a slight incline caused engine misses and backfires through the muffler. We limped home below 30 mph. I figured it was an electrical problem but cannot figure why engine misfires mostly on hills. Points and condenser were new 1500 miles ago. Any comments are appreciated. Ken