At my wit's end

Did the valve adjustment this weekend as well as replacing the HEI module with a better quality one. Car has noticeably more throttle response and power. Biggest thing now is the nasty exhaust fumes it seems to be putting out. Pretty sure it is the fuel mixture at this point. Biggest pain of the valve adjustment was getting the cover off. With A/C and the heater hoses it made it darn near impossible to get it off/on without trouble. Took it on the freeway again the other night to see how it handled at higher speeds. The car seems to like the higher RPM ranges. It handled the speed ok, but it feels like the tires might not be balanced right as there was a bit of wobble here and there. I'll be taking it on a longer freeway drive on Wens. as I take it to work.