Maybe not to you but on a 273 or 318 its not too bad and not a hard job. Maybe 2 hours with a carbide.
A set of 360's 1.88" intakes in a super ported 273 closed chamber head, a 292 DC cam, Weiand Stelth Intake and a set of 340 A body exhuast manifolds made a 1966 Dart Wagon with a 0.060 over 318 a sleeper
You work with what you have or can afford.
I would never grind the head chamber out to the gasket bore, close but not to it. You are right about problems blowing the fire ring out as the head does move a slight amount sometimes..... Harmonic distortion.....
But to go almost to the fire ring on the block side is not as bad. And only for a small section of the diameter.
