Apparently it's not wise to order the ARP Head Studs from them either. I recently sold my set to XMasta19 and he tried to installed them and they weren't right(threads are different). This is the 141-4202 set for the Dodge Neon 420a. Now I have to call ARP and see if they'll swap the set out with XMasta19 or I'm gonna end up having to refund him his money. My advice to everyone else is to buy the ARP studs from ARP.