Harmonic balancer help

I just got off the phone with Wes 5 minutes ago. After voicing my concerns he assures me that this particular balancer (part number 24278 ) is the same for an externally balanced smallblock. Whether it be 340 or 360. As he owns an externally balanced 340 himself, he was familiar with it.

I am not saying that Ma Mopar didn't have different balancers or different weights. Just that Wes says "this one" will fit both.