Agar, there is no chance in them being anywhere near that power so your sources are crazy infact I had a good In depth chat with nick waples who did some heads for dick Johnson, and iirc he has the exact figures the engine produced and I can garuntee you it started wi a 5, so where e 6s and 7s are coming from I've no idea.

You know they ran a 0611 headgasket and standard head bolts too?