Originally Posted by machine shop tom
Now that's just silly. It's more likely that that one has the least lifter-to bore clearance.
I'd say there's enough wear in the bores and the lifters are probably at the small limit size-wise. If there is enough oil flow at 1200 rpms, I'd not worry about it.
Oil flows around the belt relief of the lifter, the bore clearance is meaningless unless it's so loose as to create a leak back to the crankcase from the belt relief. Or the lifter is incorrectly machined and is missing the belt relief which would reduce if not terminate oil flow to the lifters of cylinders 4 and 2. But squirting so much oil out of the rocker feed hole that it lands on the fender sounds to me like a metering problem to the push rod from inside the lifter, more than the other pushrods are plugged up, or this is too tight in its bore. Kind of a logical conclusion because the problems seem to be after this lifter, so I'd start here and work backward.
But then I'm not there so I just have to take the clues and Sherlock my way backward.
I like to see all the push rods metering well and reasonable equally, I worry this to the point of fixing when they don't. Especially if the engine is running ball and socket rockers and sees high RPM (certain restricted classes) use as this is the only means lubricating the ball and socket and cooling the same and the valve springs. So unless this is some street junker rebuild, I rather think he has grounds to be concerned.