Rebuilt 273 - starting for the first time! Help!

Might want to take a peek and see that the distributor drive gear is pointing at the front left manifold bolt,at TDC.

Some will say it doesn't matter as long as blah blah blah.

But I like to do things the way the factory intended. No questions that way.

Put the motor on TDC.
Pull the distributor.
The groove on the dist gear should face the front left manifold bolt.
You can either eye it,or use a straight edge.
If not,back it out with a screwdriver,and reinstall it so it is in alignment with the front left manifold bolt.
Now reinstall the dist so your rotor faces the same bolt.
Leave the motor right there (TDC)for firing.