rich or lean?

Ok, I'm a little confused. I've had this problem with my Stang for quite some time now and I can't figure it out. She runs great with good power but it stinks sooooo... bad sometimes I have to get out and walk away. It used to smell super rich with the Holley 1850 no matter where I woul jet it, and when I'd turn in the idle adjustment screws nothing would happen. Recently I put on a Road Demon 625cfm, now when I start it up it smells super lean, to the point where it burns my eyes and the back of my throat. So first I adjusted the choke, nothing. Next the idle mixture and I have the same problem as last time, no change...even all the way in. So I re-jetted 2 sizes, still nothing. Am I reading this wrong or what?

By the way no vacuum leaks or fuel leaks anywhere...already checked.


Ken

Sorry, its a 66 coupe, 74 302 0.030 over, Twisted wedge alum. heads, forged 9.5 to 1 pistons (matched to heads), Edlebrock performer Rpm mainfold, MSD 6A ignition with Mallory vaccum adv. magetic pickup distributer (36 deg total advance @ 3500 rpm), flowtech headers, Road Demon 625 carb. The smell is coming from the tail pipes only. It doesn't come into the car at all, but when I'm outside the car, mainly on startup, it stinks real bad. By the way on a couple hard acceleration, high speed runs I pulled the plugs and they are a nice medium tan color, little to no spotting, no oil, no carbon.