292H Comp Cam, reusable?? How to tell.

Soo...in my pile of 340 junk, I found an ancient standard LC-340 piston with rings installed 929.8 grams (2lbs .8oz on my cheap scale). And on a .030 2316, without rings, it weighs 895.8 oz. (1lb, 15.6oz). Side by side comparison with the pin installed 1/2 / 1/2 to each piston, its basically from the chamfer and up difference in compression height. Info I found said .100".