Wrench there shouldn't be any issues. In fact I think you'd have a hard time using bolts any time with these heads. When I threaded a bolt into a couple of holes beside the ex. ports there wasn't enough room for a socket to be used. Look right there beside the #6 ex. port, if not for the small diameter 12 point nut I don't think I'd have been able to torque it. These are from ARP.
Hope that helps, Steve
