Pushrod oiling - do I need it?

Yeah, I tend to agree with the above. Sorry Oldmanmopar, even though I sort of understand the concept, I'm really not seeing the benefit of the recess in a real-world situation. Besides, reason says that if cutting a relief in that particular stud is 100% necessary, ARP would provide a modifed stud intheir kits. Studs are simple things. ARP would never sell them if there was a need for the end user to modify them after the initial purchase.

In my heads, there are two oil holes in the intake side of that bolt hole. As we're all aware, the oil passage that goes up the rocker stand right next to that bolt hole is pressure fed so the oil is forced up to the rockers through it. Frankly, I'm not even sure why those holes are there but my guess is they act as a bleed to slow down the oil just enough so it doesn't gush out the top.

Either way, cutting that recess in the stud would effectively reduce the oil pressure by some amount because you're adding volume to the oil path by whatever amount is represented by the area of the recess. How much is presure is lost is probably not worth debating but Boyle's law states adding more volume always reduces pressure. Always.

Plus, if you run a high volume oil pump, you're already creating a slight loss of pressure so the recess would add to it.