360 Engine cranks but won't start

10 mark on the balancer is close enough. But it's nearly impossible to get the cap in the exact right position pointing at #1 wire. what you may need (assuming everything else is in order...) is to leave the distributor a little loose and then have someone move it back and forth a few degrees around that position while cranking. Know what I mean?

Not really. When you say crank you mean by hand? I am pretty close to the #1 but will check again. The long narrow end of the rotor "nose" needs to be pointing at the #1 spark plug correct?