The rotating parts are internally balanced.

I have these three torque converters that came along with big block 727's I have purchased over the years. I have no idea if they are originals or aftermarket as there is very little marked on them, no brands or part numbers. The only things I see are the one on the right has 764 stamped in it as well as written on it and it has a capital A with a capital R connected to the A stamped into it. It also has a V and a G stamped on the backside. The middle one with the yellow cap has 764 written on it with a black marker and a sticker on it that most of the printing is worn off of other than the word stall. The one on the left has the numbers 17 and 3 and an odd symbol that looks like Y. Do any of these things mean anything? Also, is there any way torque converter can be tested at a trans. shop to see what they stall at?