Knowledge is power dude!
And I'm sure the machine shop guy would pull the engine back out, tear it down, and eat all related charges, and reimburse you for your labor for re-doing that engine since it would have mucho "lifter rattle"...not. They would blame the fail on "that dam smartazz customer didn't know what tha hail he was doin'".
If the original design/installation of probably close to half a million+ or so of the #5 cam bearings didn't matter to the "factory", they would not have engineered the way they were meant to be! Does the "factory" ever scruu up? Of course they do, but then the issue gets fixed. This was the truck bizznizz,...not the typical deetrot "big 3 don't give a shit" passenger vehicle bizznizz that is still prevalent today!
These engines were for working vehicles making wages for someone, their owners would have never tolerated engine failure (lubrication-related) when they were running fleets of five>fifty of these motors back in the day! If even one failed due to a manufacturing issue, they all would fail and the fleet owner woulda stuck 'em all up the dealer or factory branch butt!
Anyway, let's move forward.
Here's your own personal copy of the "pre-oil" document. While it is somewhat more involved than what you are doing, the process is exactly the same.
You have now seen exactly how the feed hole in the #4 cam journal aligns only twice per each full revolution of the camshaft to allow oil to feed through the rocker assembly. So you must use extreme patience in carefully rotating the crankshaft to hit that "sweet spot", don't get anxious, don't get in a hurry, take your time. Once you hit the spot, oil will slowly start oozing form all the clearance voids throughout the entire rocker assembly. Keep spinning the oil pump for at least 15 minutes once you observe oil drool, the engine will be very appreciative of your efforts in the end!!
You will also be able to look down past the pushrods into the lifter gallery and see oil flooding...if that cam bearing had not been re-positioned, the oil flow at that point would not be sufficient when the engine was actually running. This attention to detail insures success in an engine build!!
And for when you are really bored but feeling super-educated....look through this thread and you will see an example of that old adage..."you are not alone"!:
http://www.forums.IHPartsAmerica.com/gas-engine-tech/2694-no-oil-driverside-head.html