408, Small or Big Block? Need EGT Info

Well, when fuel is vaporized better, it tends to burn hotter, or at least that is what everyone I have known tells me. I know the tune of the engine is everything. I know you can't tune to something that varies as much as EGT. I just want to be sure I am not going to burn a valve or anything. I am concerned that if I kept it at cruise and it was burning at 12.5-13 AFR, it could read okay on the AFR but still be burning hot? At WOT we are talking about an extreme condition for any motor. I would like to keep it in normal hot range accelerating from 0-60, then 0-80 maybe, and watching both the AFR and the EGT at the same time. I have a camera in my car that records both gauges simultaneously for me so after my run, I can go home, bring it up on my large desktop monitor and read the gauges. If it is too hot, maybe I could add more fuel, change timing, etc? I was really kind of just hoping there was a range within which the EGT would be considered okay temp, and what tells you to shut off your engine and try again later. I am not sure how much the AFR is going to be affected by my mod. Will a better vapor burn hotter? Will the better vapor keep the same AFR but be more powerful and produce more heat? Or will it change the AFR and the EGT when I really get on it. Isn't there some temp that is too hot for the valves to keep up with? I noticed when I decel the temp goes down, so if it starts getting too hot I could decel to a stop and let 'er cool down, but I have no idea what hot and too hot is. I'm not "Generically" tuning an engine to the EGR, I am looking to see how much heat is produced by a better vaporized mixture, and I don't have a million bucks to do it with. I can make a run, make a pit stop, put the device on in 10 min, and go make the same run, in the same place, on the same day, 15 min apart. That is pretty dang close to the same conditions, so the AFR and EGT should be within 0.3+/- AFR and I guess maybe 500 +/- EGT?