Pushrod oiling - do I need it?
Consider the crank case pressure and mainly windage .. and its effect on oil return... oil is airborne at rpm coming off of the internal components. The pushrods maybe hold about a tea spoon each. It's not much. More oil is coming off the cam/lifters than the push rods at rpm...consider uaing a valley baffle.
Run it, inspect it.. then change what's necessary if anything at all.
This is an exxageration but trying to oil the adjuster tips through the pushrods is sort of like filling up a Dixie cup with a garden hose. Of course some water will go in the cup but the majority of it won't and will invariably just splash on the ground. Even if you reduce the volume coming out of the hose, the cup will still fill up pretty fast. Once the cup is full, everything else you attempt to put in it just becomes excess. Now imagine 16 hoses trying to fill 16 Dixie cups. OTOH, there would be little point in adding extra volume by a slow drip if another source (shaft oiling) was maintaining an acceptable volume for the purpose at hand.
When you pop a valve cover or the intake there is always some amount of oil sitting in the head or at the bottom of the lifter valley. That oil isn't in the crank case so clearly drain back is not instant nor is it 100% efficient. Just saying that if you're pushrod oiling
and shaft oiling at the same time and the amounts of oil sitting in those areas increases beyond what's normally acceptable you might have a problem elsewhere.
I still maintain that the rate of drain back
has to be lower than the rate of the pressure-fed oil being forced through an orifice. To me, that means the excess volume increases faster than what's being pumped out through the galleries (or pushrods) which effectively decreases the available volume of
pressurized oil to the galleries by that same amount. It's probably not much but it is something.
The whole question is whether the stock system is adequate for whatever level of abuse you're carrying out. With a HV oil pump, one would hope it's sufficient. Like you said, only way to find out is to run it and inspect things. Not sure if a specific pressure for a given rpm becomes a warning sign. If you're tunring 7,000 rpm on a regular basis and only seeing 60 psi maybe you'd want to check things a little more often or it might even be too late already.
Honestly, I don't know if any of this is exactly right but I do think there is some truth to it since pushrod oiling generally requires reducing or blocking off the oil going to the rocker stand in order to
prevent excess oil from going to the head. Take that for what it's worth I guess.
Last, reason says that if pushrod oiling was truly necessary for a certain level of perfromance above stock, manufacturers like ARP or Hughes would design their parts to facilitate it. From what I can tell, that's never been the case for your garden variety street/strip situation so it's really not worth fussing over something that is most likely not needed.