BEFORE disassembly, if possible perform a cranking compression test and a cylinder leakdown test on each cylinder. That tells you the basic sealing characteristics of the rings, valves, head gasket.
BE SURE YOU CAN GET PARTS--PISTONS, BEARINGS, TIMING GEARS, GASKETS, and all the other items needed. Supply chains are STILL in sad shape after the Communist Plague. My favorite machinist is still complaining that he can't get parts required, so blocks and cylinder heads at his shop are taking up time 'n' space while he waits weeks or months to receive what used to be "common" items.
I used to stamp connecting rods and caps. Learned later that
the better process is to use a vibrating engraver.
Paint pen? Will never stand up to proper cleaning.
Rod resizing? Have the rods CHECKED for size. Most or all of them will not need resizing unless you insist on replacing the fasteners. Resizing changes the center-to-center length (although not by much.)
Verify piston-to-head clearance. Most engines have WAY TOO MUCH. This reduces turbulence in the cylinder, making for a lazy burn and needing excess timing advance. It's made MUCH WORSE by replacing OEM steel-shim head gaskets with aftermarket composition gaskets that are twice as thick as what the engine was designed-for, and aftermarket replacement pistons that are sabotaged by design with too-little compression height. Many "replacement" pistons are .010 or .020 too damn short.
The usual "fix" for excess piston-to-head clearance is to mill the block decks. Be sure the machine shop centers the block off of the main saddles, so the block decks are even from front-to-back, 90 degrees to the crank centerline, and even from side-to-side. Factory deck machining is not accurate enough to base the new machining from, and besides--the block distorts over time and with use and heat-cycling. What might have been "accurate" when new, probably is not now.
IF (big IF) the main caps are being align bored/align honed, do that before machining the block decks.
Ideally, the cylinders are honed using a torque-plate and head gasket, to simulate cylinder head/head bolt distortion. The bores need to be straight and round AFTER the head is torqued into place, not when the block has no stress sitting in the machining fixture. "Good Luck" finding a machine shop with an Intercoursable-Harvester torque plate. Depending on the equipment used, 50--80% of the benefit of a torque plate can be accomplished by using short bolts and a stack of washers or a solid tubular spacer on each head-bolt hole, with the bolts going into the block the same amount (same thread engagement) as the actual head bolts would. Torque to spec, hone the cylinder.
In particular for head bolts and main-cap bolts: If there's a washer under the bolt head (usually not on cast-iron parts) do not apply lube between the washer and the casting. Lube (or seal, as appropriate) the threads, lube under the bolt head, (between bolt head and washer or casting) but not between washer and casting. Use a torque spec appropriate for the lube you're using. In general, oil requires a higher torque than moly-based fastener lube.
I will not allow "kitty litter" or "Oil Dri" granulated clay in my shop. Too much dust, contaminates everything. I wipe-up spilled fluids with rags, then clean with detergent and water. No dust.
DO NOT dunk the pistons/rings in a bucket of oil. Wipe the fresh and cleaned cylinder walls with a hint of ATF on a non-linting rag, oil the wrist pin. Rings get oiled during installation onto the pistons, wipe the excess from the piston. Too much oil on the rings slows seating.
I disassemble and clean new or used hydraulic lifters before installation. New ones are often contaminated with anti-rust preservative, old ones will be filthy inside--the oil path into the lifter is relatively large, the clearance for oil to get out of the lifter is microscopic. Grit and sludge get into the lifter in use, but can't get back out. Hydraulic lifters are like miniature oil filters. Disassemble them ONE AT A TIME because you do not want to mix the internal pieces from one to another. Lifter plungers are select-fit into the lifter bodies. That's what makes for the microscopic clearances.
Once the lifters are cleaned and re-assembled, I pump them full of ATF (flows easily at room temperature) using a pump-style oil can. This allows me to
verify lifter leakdown rate, and also assures that the lifter can flow oil to the pushrod seat (if required.)
SV rocker arms are probably totally worn-out. In fact, that's common with most engine families. They'll wear the valve tips, too.
EVERYTHING gets cleaned in hot, soapy water. Used parts, the block, (rifle-brush EVERY oil gallery) even new parts straight out of the box or bag. Compressed air to dry. Some sort of metal-protectant to prevent rust.
Remember that the SV-series engines are timed off of the #8 spark plug wire, not #1 like most engines.
EVERYTHING that needs lube on initial fire-up was provided with assembly lube. There is NO reason to go crazy "priming" the oiling system, ESPECIALLY when the engine has a submerged oil pump. Some guys prime for ten minutes, turn the crank, prime for ten minutes, turn the crank...that's insane. "Priming" is optional. You're purging air from the pump and the oil filter, and filling the major oil galleries by spinning the pump.
If "priming" takes more than one minute, something is wrong. You're DONE priming when you show oil pressure on the gauge. You DO NOT need to squirt oil over the rocker arms. DO NOT spin the oil pump with a high-speed 1/4" or 3/8" drill. A 400--500 rpm 1/2" air drill (doesn't build heat when used) is ideal,
only because drills that spin slower are really uncommon. At idle, the oil pump is turning ~350 rpm.
When the engine is fired-up, "break in" the cam/lifters as usual procedure, then re-check all adjustments, top-off fluids, tension belts, etc. IF (big IF) you use thick, moly-based paste on the cam lobes/lifter bottoms, change the oil filter if not the oil as well. Moly-based paste assembly lube can plug an oil filter in twenty minutes.
I like to sacrifice a Treasure-Yard valve cover pair, so that I can verify that the pushrods spin. Paint a vertical stripe on the pushrods with a paint-pen, When the engine runs, assure that each pushrod spins. If a pushrod doesn't spin, the lifter isn't spinning either--and it'll wear-out the lifter and cam in short order. (Pontiac valve cover set shown.)
Head for a deserted highway, accelerate, put the truck in HIGH GEAR, and nail the gas pedal. When you get to highway speed, coast down to the lowest speed the truck can handle in high gear without problems. NAIL the gas again, get up to speed, coast down. Repeat until it stops being fun. High cylinder pressure seats the rings, high vacuum when coasting brings oil up the cylinder walls to wash-away oil particles. You want high load, but not high RPM. 3,500 rpm is PLENTY.