I talked to ARP and they said that the old style headstuds were replaced by new ones. SAME PART #. The new studs cost about $180-200 compared to the older ones being about $150. The guy at ARP said they are redesigned units that are supposed to cure any issues the old ones had. I called up Greg V and he has them or can get them. I will see if he can send me pics of the new studs and I will put some pics of my old ARPs up.