Piston ring question

[wirehairs]

I'm redoing a head on an 82 DOHC Maxim 400 and figured I might as well replacing the rings, especially since I broke the 2nd ring on one of the pistons while removing it. My ring end gap is within spec for the remaining rings. But since I busted one, am I correct to say that I should replace them all? I could get a used one off a parts bike I have. If I get the ring end gap to be comparable to the others, is that all that matters? I don't have a tool to measure the bore; with only 15K on the engine, I wasn't going to worry about it. I'm also unsure when oversized piston rings should be used. Any advice?

 

[XSLeo]

It's your bike so do as you want.
Me, I'd get things measured up. Most shops won't charge much to do the measuring. Cylinders and pistons. Use these measurement to determine wear.
Your repair manual lists the clearances and tolerances.
If things are ok, new rings don't cost much.
Leo