I have a strange misfire on my new purchase (92 LT1). It will give me a rather hard misfire at about a 70% throttle at 1500 rpm. Below that throttle position it gets better and even goes away at very light throttle. Above that throttle position it even seems to be less severe. Also, there does seem to be a little lumpyness at idle which would indicate a random misfire. However, everywhere else in the rpm range it is smooth. I am going to throw new plugs and plug wires at it to see what happens but I am curious if this problem rings a bell to any other members and what you did to eliminate it?