You may be surprised, my 850 ultra usually runs within about 150 degrees cylinder to cylinder. A guy should only really be concerned if one is significantly different, say 4 or 500 degrees. The mag side will tend to read a little hotter than the PTO side given the coolant flow and positioning in the chasis, and the center usually somewhere between the other two. But there again, this does not ring true of all sleds. An EGT gauge is more of a watchfull eye that will report of a problem early on, than anything else. Get the thing together, tuned right using your plugs and piston wash as a guide, take note of the average exhaust temps, then just watch for anything abnormal afterward.
