I drive a 1995 4.0 SSE. It is supercharged and has 3" exhaust with no cats. I just recently removed the heads and had them gone through and prepped to Callaway flow specs then decked for true. I put it back together with composite gaskets and cleaned and sealed everything on my way out. She ran really well for a while but now has what I would call a "poor" idle as well as a knock and lots of black smoke when pushed. She seems to be running very rich and mpg's are down I always run premium fuel. Cylinder compression checks show no problems and the OBD II computer shows no fault codes (I use an Actron computer which actually reads codes and erases on my 95). Would love some input.