Highest flowing sbm heads?

I have not read through this whole thing so I apologize if this is a re-hash but where do the Indy 360-1 or -2 heads fit in here?

Also, are the Bloomer heads readily available for purchase? As has been mentioned previously, there's no info out there on where you can get them, how much they cost, etc. Is he even still doing them? I have one of his 4" cranks in my 416", it's a nice piece.