Several years ago before the block was machined, I spent a lot of time de burring it inside and out and made sure all the openings in the lifter valley were smoothed. The lifter valley is also painted with
Glyptal which supposedly promotes drain back by keeping the oil from absorbing into the porous surface of the cast iron. There really isn't much casting flash on the aluminum heads I have.
Not sure if you had a high volume pump when you had things burn up on you but I do. At one point I bought one from
Precision with moly coated gears but I inadvertently cracked it trying to install it over a stud that was too long. I got regular HV72, swapped in the coated gears and enlarged the entry by copying what Precision did. Works fine with the standard 3/8 pickup. Oil pan is a
Kevko M301 with a built in crank scraper. Holds 5 quarts in the pan itself and accommodates 6 quarts in the system.
I mentioned this already but the Hughes rocker arms have an oiling hole for the adjuster tip. It's not for pushrod oiling but it does squirt whatever oil is available at that orifice out the back of the rocker arm toward the adjuster ball and pushrod cup. If there was some amount of additional, pressurized oil coming up through the pushrod to the same point that is already being lubed by the hole in the rocker, it stands to reason there would be excess oil.
With pushrod oiling, all 16 rods are always filled so there's a couple cubic inches of oil in them at all times. Compared to bearing surfaces, the areas of contact between the adjuster ball and pushrod cup are relatively small most of it becomes waste. There is no direct path for the oil to get back to the crank case so it's just sitting there doing nothing. The volume of that excess oil also ends up being more than what's in the pushrods since the rate of drain back is slower than pressurized oil being forced though a small orifice.
It's not only about getting oil to a spot but you also have to consider what happens with any extra oil that has to go back to the crankcase. Pick your poison.