I am assembling the engine from my '53 Buick Super. Had it machined, and am installing new pistons/rings/ bearings/etc.
I'm using Lubriplate 105 as the assembly lube. After assembly, I'm sure the engine will sit for a couple of years while I work on the car's body, etc. Question is, should I prime the engine oil system before laying it up, or wait to just before I start it to prime it? Thanks.

Prime the oil pump, then run the engine at least long enough to circulate oil into every nook and cranny. Engine-build oil is very temporary.

At the engine plant, they 'cold test' the engine first. This gets the oil pump going, too. If the engine passes all the requirements, then they 'hot test' (run the engine with spark) before it's shipped to the assembly plant. Assembly oil doesn't sit in an engine for more than a weekend at the longest.

You need to run your engine for several reasons. The most obvious is, "how does it sound?" If there are issues, you want to know about them now.

After your engine oil is well distributed, you can fog the cylinders with fogging spray for the two-year wait. If you do it right, there will be no rust or corrosion, and it will be "ready to run," when you are, just like a factory engine.

Speaking from past experience you need to follow the above advice. Had an engine rebuilt just to find out they did something wrong with the oil pump. We hooked up a pressure gauge and after several attempts to get prime, finally pulled it and sent it back. What a P.I.A....

Now you all make me wonder about the engine I have sitting in my garage...

Rebuilt and never ran... Wrapped in Pallet wrapping plastic with moisture absorber in it.

Wonder what it will be like if I ever need it ???

Sooner or later, you'll find out when you run it.
To ship an untested engine is unheard of. That's how the Japanese gained their reputation for quality; they tested and fixed all the problems before their products left Japan. All you see is, 'the product works flawlessly'. Only God knows what had been done to make it that way.
brh's problem wasn't unique. Whoever built it should have tested, recognized the problem, and fixed it in-house. No one would be wiser. It ran just fine after it was finally repaired. Instead, brh went through unnecessary aggrivation over an engine that never should have been shipped, and he is rightfully telling us (the internet) to beware.

I would not worry. Just assemble carefully and store indoors at a constant temperature. Avoid cold temps followed by warm humid air that will condense outside and inside the engine. Maybe for good measure leave the rocker shafts off so that the valves are closed and rotate the engine once every month or so. I have seen rusting/corrosion on the cylinder walls of engines honed with a coarse stone and cast iron rings installed. Don't run it until you are ready to drive it.
Willie

No wonder you're getting rust. Pull your plugs and fog those cylinders with WD-40 (or equiv.). I would do it every three-four months. In fact, very light, thin, oil (like WD-40) is what you want to use when you initially start your engine. It penetrates the iron bore & rings, inhibits rust, and promotes engine oil to displace it.

A course crosshatch is much better than having smooth cylinders, especially when using penetrating oil. Smooth bores cause piston rings to hydroplane, and that is what causes your engine to burn oil. "A smooth bore is an oil burner." - Dave Dare

Hello 1953Buick:

I understand that the first 30 minutes of runtime on a newly rebuilt engine is very important. The camshaft/lifter break-in is critical (for both solid and hydraulic lifters). A special lube is used to coat the camshaft & lifter mating surfaces. Crane Cams has an good article on this procedure:
Crane Cams Break-in Article

Good Luck,

Paul

Personally, I like this part: "...be sure to check for any leaks and check out any unusual noises. If something doesn't sound right, shut the engine off and check out the source of the noise." - This might be a good reason to run the engine as soon as it is built.
I cannot agree with this: "...the break-in continued for a total run time of 20 - 30 minutes. ...At this point the initial “breakin” is complete." Oh, no it isn't.
The entire engine needs proper break-in. Crane does a wonderful job discussing the valve train, but cams only go HALF the rotation of the crank and pistons. What about proper break-in for piston rings? Some rings take forever to seat because they didn't get a proper break-in.

Here's what Hastings Piston Rings has to say: Make a test run at 30 miles per hour and accelerate at full throttle to 50 miles per hour. Repeat the acceleration cycle from 30 to 50 miles per hour at least ten times. No further break-in is necessary. If traffic conditions will not permit this procedure, accelerate the engine rapidly several times through the intermediate gears during the check run. The object is to apply a load to the engine for short periods of time and in rapid succession soon after engine warm up. This action thrusts the piston rings against the cylinder wall with increased pressure and results in accelerated ring seating."

I suppose if I had a 426 hemi, I would look for a big mountain, just to 'load' the engine ten times.