I have found when using my infared temp gun, the zoomie temps vary depending on the coatings on the pipes. I have had my pipes, chromed, VHT painted, High Temp ceramic coated, and even raw. I use the temp gun during warm-up to adjust the injectors to get them even temps. The EGT temps will vary depending on cam timing and yes tune-up. 1300° is too high for my combo, but some cams with more overlap can put too much fuel in the pipes and burn the alky in the pipes, so you can get higher EGT's. That's why it's hard to compare different racers EGT.
The best is to read your spark plugs, I use NGK because they are cad plated, and will burn off showing me how much heat I'm getting on the plugs/ in the motor. I have recommended to other racers that when they are working on their tune-up to install at least one new plug for each run so you can see what's going on. Example 1'st run of the day put a new plug in # 1 hole, 2'nd run new plug in # 2, etc. Just keep track of which cylinder has the new plug, I have a tool tray with S-plug holders, I just keep the run plug in the tray to remind me which has the new plug.
Have Fun,
Jon Hansen, Hayden Wheels