I'm not the best qualified to answer this, but yes. Pull the plugs, shoot some oil in there, let is soak over night, shoot some more oil in there, turn it over a few times without the plugs and if all sounds good, put the plugs back in and fire it up. Good luck!

I don't have personal experience with this, but .....

Most instructions on the internet say to squirt
Marvel Mystery Oil in the cylinders.

But your engine may not have been sitting long
enough to require a special oil like that.

Excellent, I have plenty of that.
That's what goes in the air tools.
I feel better about that oil..
Thanks, guys,
I'll check in here before I shoot anything in, in case someone has a different idea

Muh 29 year old neighbor came down, pulled the plugs,, and boy were they messed up looking,, used a battery water bulb, put a bit of oil in the holes, pumped some air in, making a mist, pulled the fuel lines from the frame mounted filter,, stunk like crap...
So now I'm a bit concerned about what the injectors are gonna deal with if I don't find a way to flush the fuel rail..
Tomorrow, if I have a good day, we will use a ratchet and spin the motor,, if there are no odd feelings of resistance, then the starter will spin it, then new plugs go in.. and we hit the starter..

Unless some genius recommends I figure a way to flush the fuel rail..
I'm thinking pull the most forward injector and at least blowing the rail out..

Mechanic yes , genius I’m not !

JOG

My first question is :

What's in the crankcase ?    You really don't want to start or circulate 6 year old oil in you motor do you ?
I'd put a new filter on it too.  

My second thought is :  

Plugs out
Some really thin oil on top the pistons to help free the rings from there rusty places on the cylinder walls soaking for at least a day is a good idea.

Third thought :

Some STP in the new crankcase oil to fill the pits in the rusty metal parts is a good thing.   Rust can act like sanding compound till its polished a bit  , so spinning the motor for a nice long while might be a good idea.  

Fourth thing :   After it starts and idles for the first heat-up cycle  ---  might be a good time to put a new oil filter on it.  A $8.00 oil filter at the right time might be $$$ well spent .  

That's all I got , and is exactly what I would do in your place.

I would first crank it over and get oil pressure.  You don't want to take the filter off.....and then have to pump the filter full of oil before any of the bearings get oil.

What kind of truck is this.....how many mile are on it?

Modern engine aren't built for thick oil - adding STP or Lucas may not be a great idea for and engine that still has tight bearing surfaces.  What weight oil does this engine use (according to the owners manual or the top of the oi cap).