Technical I let someone else touch my 235, and now its upset with me

Problem with projects like this is you really can't just cruise them if you have pulled them out of mothball and expect them to be reliable.
Need to get them good and heat soaked, 'run em to failure', once they start acting up trace down the problem and then keep doing it til the car is granite.
If you have a mish-mash of parts, you will also need to verify they are compatible. Does the ~'60 235 have all the '50 216 bits, was the system converted to 12V? If it is still on 6V was everything on the engine changed to work with 6V?

My crap shot theory, if the shop had it for a while they may have started/stopped the truck a few times without letting it get up to temp. This would cause a few problems.
Battery would get drained down from being started and not driven(low voltage). Especially if you still have a 6V Gen system.
Plugs may be wet/fouled out from lots of cold(choke on) starts and not allowed to self clean.
At idle it runs like crap due to low voltage and the GEN not really keeping up with the system.

As mentioned you need to get down to basics. Air, Fuel, Power.
Get a volt meter, a Vac/fuel pressure gauge, and a compression gauge.
Go over everything, look for loose, broken, missing, items. Especially items that you 'just replaced/repaired'. Trust but verify(everything).

Make sure there isn't some restriction in the air cleaner/intake/exhaust system.
Drop the down pipe from the exhaust manifold to eliminate a muffler failure.
Check what the vacuum is at idle and at higher engine speeds, do this before removing the down pipe and again after.

Verify the fuel pressure is adequate. Even new old stock pumps may have been made before ethanol was introduced, ethanol will eat diaphragms on older pumps. I've had this happen on a few revived projects, pump may be new but if it is old stock it'll disintegrate. This will cause two problems, low fuel pressure at idle and a bunch of junk in the fuel bowl. Rev the engine the fuel pump may still make some semblance of pressure/flow and get fuel to the carb and the engine runs slightly better at higher than idle speeds. Engines can run very lean, a fart of fuel will get an engine to run, too much will cause it to run boggy. Junk can clog the system, or jam a needle/seat open and flood.

Verify battery voltage OFF. If its 6 or 12 Volt system, the battery should read about .4V higher than that wither everything off. Anything less is a drained/dying/undercharged battery.
Verify battery voltage running. GEN systems are a bit fickle at idle. Verify the GEN is working correctly and the VR is not crapping out or out of adjustment, or incorrect VR for the application.
Verify the engine, battery, body are all properly grounded and bonded to each other.
Any questionable links, joints, or connections should be redone. Clean and tight connections. Use a little OX-Guard to aid in preventing corrosion at connections.

Pull plugs and verify they are not wet or fouled out.
Reattach spark plug wire, ground electrode to block, have someone crank the engine. You should have a bluish white spark, if it is orange the spark is weak.

Finally do a compression check.
I doubt new oil would wipe out a cam in short order at a shop.

I always find going over everything about 2-3 times on these kinds of projects, you fix it then everything, drive to failure, find something else shit the bed, drive to failure again, and again drive to failure.
Find the weak links and repair/replace.

 

If he has a 60 235. It likely has Hyd lifters. and hyd lifters on a 235 where marginal at best. I always replaced the 235 hyd lifters with new solid lifters and It was a great improvement.