You'll find that the EGT value changes a great deal with respect to the probe's insertion depth. From experience, those numbers seem good so long as the probe has at least 1.5mm exposure to the exhaust flow. If its less than that and you're getting above 600, you may have the probe positioned radially in a hot'ish quadrant. Generally speaking though, if the engine is acting up and the EGT's are starting to become a bit suspicious, you'll see it start to give a red glow in normal daylight conditions. Red glow in the evening isn't indicative of a problem normally though, unless it's REALLY red. Short story, you're probably OK.

Scratch building a wheel ain't easy. Well done! Keep a close eye on it though. A good friend did the same on one of his KJ's and eventually converted to a cast version...

Kelly