Going by your Sig, you're currently running a VE fueled 1st gen head. It came from the factory with a boss cast/milled/drilled and threaded to mount the VE's throttle bellcrank.
A newer 2nd gen or so head will still have the boss cast in it, but it won't be milled/drilled and threaded. You'll have to do that yourself. No big whoop.
(Don't know about the Hammy Head)