Briggs Twin Valve Play (wiggle)

It's been years since I played around with small engines. My question is how much wiggle should there be with the valves on a side to side motion? I have spent most of my time playing with SBC motors and I know you should not compare apples to oranges. The engine is a 16HP Briggs opposed twin flat head and there are no removable valve guides. The valve stems are hardly worn and and measure almost like new. So the only possible play would be from the drilled holes in the aluminum block. Valve seats and the valves are in real nice shape, just don't know if the block is too worn or not.

If they are pretty good they shouldn't move much. Maybe just enough to see that it moves. But I've seen some with quite a bit of play. Still seemed to run ok. Not much you can do really, unless you wanted to get bronze valve guides put in, which probably isn't worth it. The cylinders are probably pretty well worn too if the valve guides are beat. I/C engines have a bronze guide on the exhaust valve. The go kart/quarter midget guys get them pressed in to both when they build an engine.