I bought a truck from a guy that got from his dad. It hasn't run in several years. He doesn't remember why it was parked. It barely runs. Put #1 piston at top of cyl. on compression stroke. The notch on the harmonic balancer is at the bottom of the engine at the 6 o'clock position. Are the timing gears aligned wrong?

 

Maybe. Maybe you are looking at the wrong timing mark as later ones had a notch for factory equipment plus the grove for timing.

Or maybe the damper ring slipped.

I would check the compression. If they are all uniformly low - like 50 psi - then it may be timing gears.

 

Compression on all cylinders around 120 psi. I installed: new fuel tank with fuel pump,plugs,wires,Ecm,coil in distributer,oxy sensor,fuel injectors. Looked for vacuum leaks by spraying carb cleaner, engine revs a little,fixed the hose. Plenty of exhaust coming out of tailpipe(cat converter). Could smog system cause it to miss badly?

 

If you put the #1 cylinder at TDC and the timing marks aren't lined up on the balancer, then you may have a slipped balancer. The vulcanized rubber can lose its grip, causing the outer ring to move independently of the inner ring. Any movement at all, and the timing marks won't be in the right place. At this point, if you time the engine off of these marks, it's going to be WAY off.
I had a bad one and this is how it looked after I pulled it off.




IF it's your timing gears, you'll have to remove the timing cover to check them. The timing gears should be aligned in a way where the timing marks on each gear are lined up perfectly. If this isn't the case, your timing will be off no matter what.




For the moment, ignore your timing marks on the balancer and just time it with a vacuum gauge. Get a good vacuum gauge and put it on direct manifold vacuum. Get it running, disconnect your vacuum advance, and then rotate the distributor/advance the timing until you achieve the highest vacuum reading possible (it'll peak after a while). Now, rotate it the other way/ retard the timing slightly until the vacuum drops to about 1 to 1 1/2 below the highest reading. Tighten down your distributor and hook back up the advance and see how it runs.

By the sound of how your timing marks are lined up, I'm guessing you have a bad harmonic balancer and someone still tried to time it off of the marks.

 

Good explanation, AbandonedBronco!

 

I finally did find the correct timing mark on the harmonic balancer. It looks like my timing is correct so I didn't have to pull the timing cover off. I finally decided to pull the fuel injectors out again and found two that not working correctly. Tried to clean them but wound up replacing them. Runs a whole lot better but still has a miss. Thanks for all of the advise, it was very helpful. Found a couple of small vacuum leaks and fixed but still has a miss.

 

Awesome! A miss or two is a whole lot closer than you were befoer.
Keep it up and it'll be running like a top in no time. Nice work.