Thanks you all for the advise... I appreciate all the feedback....
And Yes Sam actually its both..... I am actually seeing some light black smoke from the exhaust when im out on the interstate.. I really dont know too much about the timing and all so I cant really offer much insight on that.. I know I've had it checked several times by my mechanic and he swears its right...
Ive been thinking about a few things..... and Im gonna feel so stupid if this is my problem.....
I do have an eddelebrock 600 cfm carb with the manual choke... But I never got around to installing the choke cable... so right now I have nothing hooked to the choke linkage at all.... on a cold day I would just pop the hood and push the choke linkage with my finger... Is it possible that after the engine warms up to normal operating temp and as im driving it... the suction from the carb could partially be closing the choke flapper causing it to run rich?