Reworking the 273 Adjustable Rockers

moper said
I guess I'm not sure I understand the need for this mod. At no time do the rockers get "full oil pressure" unless you change the method of oiling the top end. In factory oiling the holes line up to expose the shaft to operating pressure for a few degrees out of 360°. I'm guessing something like 15-20°? So what's felt is a pulse which is then dispersed over the whole shaft because the oil pressure is leaking out the shaft and the sides of each rocker.
I wouldn't use these rockers for "big springs" or "big rpm". And if I was building for those, I'd probably be swapping to pushrod oiling.

Before NHRA changed the stock class rules these and the Isky look alikes were the only adjustable rockers you could run.
The cams with the full groove on the #2 and #4 journals have full pressure to the heads. At 6000 and above the hole in the cam an block are lining up so fast it has back pressure in the rocker arm shafts. That pressure is causing the rocker arm oil to blast out of the holes instead of flowing out an doing it's job.

This modification is not for a street car that sees 2500 to 4000 rpm most of the time an maybe gets run thru the gears once or twice a week.

This is not the W-2 rocker if you look at a W-2 there is no top hole and the hole at the push rod is welded shut. It comes from Mopar that way. The W-2 also have the hole for oiling the valve stem underneath the arm like I'm doing. I guess you could say I'm updating to the W-2 design only I'm not going to bush my rockers.