Here's what works for me:
When I have the engine on the stand, buttoning things up, running wires, etc., I will watch the #1 exhaust valve until it opens and shuts. The intake valve will open at this time and when it's starting to close, I'm looking at the balancer. I keep turning until I hit 30° BTDC and then put the dist cap on with the rotor pointing at the #1 plug wire.
This is the way I've done it for years, and barring something goofy like something unplugged, no gas, etc., the engine will fire on the 1st revolution. Usually it will just take a couple of degrees correction with a timing light once it's running.
My guess is that it's retarded. Normally a retarded ignition timing will pop back, advanced will crank slow. If everything is right, set it the way I described and I promise it will start first lick.