If you install a performance cam in a low compression engine it is going to stink out the exhaust. Any performance camshaft changes the rpm range the engine operates efficiently at to a higher rpm range. It also reduces cranking compression. The smell is unburned fuel, because the engine has enough overlap that it is not burning the fuel charge. The loping at idle that everyone likes is because the engine is not efficient at that low rpm range anymore. Yes, you can advance the timing, play with the idle circuits of the carb, and other patches but bottom line is if you install a camshaft in a low compression engine it will make hydrocarbon emissions at idle and stink. First thing I would do is take a cranking compression reading, if it is below 130 lbs no patches are going to remove the stink. Best bet would be to advance the cam timing to help the issue. Cam timing is different than ignition timing.