The 452 heads in the pic have already had the guides replaced.
Do they need replacing again?
Since the real machine work has already been done on those heads........If you already had a decent mic and some split ball gauges, you could probably do a half assed guide replacement and sizing for a couple hundred bucks.
Of course, if you really wanted them straight and round, you’d need a guide hone($600+) to get them correctly sized for the valves, and a guide bore gauge($1200) to accurately measure them...... so you know they are actually straight, round, and to size.
Plus you still need the guide driver to remove/install them, and some sort of spot facing tool to trim the length after they’re installed.
