individual egt's
 

Just out of curiousity the other day i thought I would check my egt's at the header about 1" from the flange at an idle. I noticed there was up to 300 degrees difference between all of the cylinders. I set the idle up to about 2000 rpm and there was still the same difference in temp. I am using a set of used green tops and wandering if they need replaced. Has anybody else checked there egts with a temp gun at low rpm. What is the normal variance?

It depends on several factors, including load, and where you're hitting the tube with the temp gun. A straight piece of the tube will have a lower temp than the back side of a bend. If you can hit each header at the bend, that will be your most consistent place from cyl to cyl.