The only Hemi balancer I have seen are ones on the web in images. They are usually thicker and squared off like 440/383 internally balancers. The latter are usually only about 1" to 1.25" thick and the former almost 2" thick. The chamfered edge was NOT cut by a machine shop, the late 440 cast crank balancers came like that. Please reference the link in my post #4. The cutout is on the back side of the balancer for the offset weight. Just because the build sheet says forged, doesn't mean it is. They could have made a mistake when writing it up. The ONLY way to verify is to pull the pan and verify the wide or narrow parting line on the crank throws. Can't say that you can't balance an internal steel crank with an external balancer, but I would think a lot of material would need to come out of the last counterweight. If it runs fine, and you don't want to go inside to verify the rotating assy, then don't, but I would lean towards a cast crank is inside.