Whats everyone's thoughts on B/500

There are 3 rod lengths I know of, the 6.76 stock length 440 LY (heavy) rod, (451) the 6.535 rod used in the 496 and 512 motors with a 4.25 stroke, and the stock 400 rod at 6.38 I think? This rod has been used in the 451 also. I'm using the 6.535 length in my 512 build. Requires an oil ring support spacer. I see no problem doing that, unless you forget to put it in there. LOL