Nice truck, You are just like me-starting a first time project. My '37 1/2 ton sat on blocks in a barn for 50 years so we're about even.
One thing I did was pull the spark plugs and dump tranny fluid down the cylinders. I let that sit for a couple months while I tinkered with
other stuff then got underneath and turned the flywheel by hand. I changed the oil, pulled the distributor and stuck a screwdriver in a
drill to spin the oil pump and prime the system. If you don't want to have to pull the oil pan to fish out the screwdriver like I did, be
sure it's firmly in the drill chuck. (Live and learn).
Not knowing if it was going to run anyway I put a brass brush in a Dremel tool and polished the contacts in the distributor cap.
While I had the distributor out I polished the points and cleaned and gapped the plugs. After replacing the fuel tank and lines I
rebuilt the fuel pump and carb and by golly I got it fired up! Now that you know if the engine is going to run (or not) you can decide
what's next.
Good luck