Dan, yes, Mike did suggest lapping first. I did let the EGTs get hot in the past because i took mikes advice regards to EGT temps being meaningless. I will keep them down while in cruise flight from now on. As an asides, i have been under the impression that 1100 Hobbs is pretty common to replace a jug.
Mike is correct on both counts.
In sutu lapping ("the rope trick") is a method of cleaning a seat and valve's mating surfaces. It will not permanently cure a valve sealing problem created by misalignment, or if the original seat cutting work was poor. It mostly just clears deposits, but sometimes it's all that's needed.
Old school production valve seating is done with a shaped stone, followed by lapping. The lapping smooths the contact face, and identifies its width and location. Photo coverage of the process here:
https://www.kitplanes.com/how-the-pros-do-it-5/
Much of the engine world no longer uses abrasives, instead employing shaped cutter inserts. Barrett, for example, switched to a Serdi machine years ago.
https://www.serdimachines.com/uploads/6139c95b081ee/techno-live-pilot.mp4
Abrasive or cutter, the key is an accurate relationship between guide and seat. If it's not there, a lapping fix will be temporary.
Mike is also correct in that there is no EGT temperature limit for a normally asperated Lycoming. The temperature you see on your gauge is only an average anyway, not the actual gas or valve temperature. For us, high exhaust gas temperature is only harmful given one circumstance, poor valve seating. If the valve does not seat properly, it cannot transfer heat to the cylinder head. The non-seating portion of the valve circumference gets hot, sometimes hot enough to melt.
I typically cruise at ~65% and peak EGT. Recent leakdown was a 77 and three 78's, at a little over 1000 hours. Excellent valve seating; thank you Monty.