Rebuilt 318 Refuses to Start

Yes CW as you look from the front of the car towards the engine.

Spinning the cam 720 degrees puts it back right where you started. I am not clear what you are intending to do with this tactic.

Do this: If you can, get and use a piston stop into the #1 spark plug hole to find TDC.
1. You insert the stop in the #1 plug hole and thread it in a bit and slooowly rotate the crank CW until it contacts the stop. Put a mark on your damper aligned with the 0 timing mark on the timing cover.
2. The rotate the crank back CCW until it contacts the stop again. Put another mark on your damper aligned with the 0 timing mark.
3. Rotate the crank so you can see both of your marks and measure the distance between them accurately
4. Divide that measured distance in 2, and measure that distance from either of the 2 marks towards the other mark (i.e., find the exact halfway point between the 2 marks), and make a 3rd mark. When that 3rd mark (which is exactly halfway between the first 2 marks) is aligned with the 0 mark on the timing cover, you ARE at true TDC. That 3rd mark is the REAL #1 TDC point on the damper.

If the damper and crank are machined accurately, then the original mark on the damper and your 3rd mark from the above procedure will be exactly the same. If not, then the damper or crank have machining errors, or you have a later damper on an early crank or vice versa. Use your 3rd mark from now on, for cam timing and ignition timing.

With the crank set up at true TDC, now you can install the chain and cam with the crank sprocket dot at 12 o'clock and the cam sprocket dot at 6 o'clock and use a straight edge aligned along the exact centers of the cam and crank to be sure that the dots are centered right on that same edge. IF the cam and sprockets are machined right, then the cam is set up basically right. I say 'basically right' because there can still be small errors that throw the cam timing off a bit. But small errors are not going to cause the engine to never fire off.

With the cam and sprockets set up as above, then align the distributor rotor so it points at the wire for #6, while at the same time, making sure any tooth of the reluctor trigger wheel on the distributor shaft is aligned perfectly with the metal blade in the reluctor. Again, I am assuming you are using the Mopar distributor to trigger your MSD ignition system. Please confirm this. (You are unfairly wasting people's time if you don't answer these questions.)

BTW, did you ever test your spark across a 1/4" to 3/8" air gap like instructed? You won't ever know if the ignition system is working right until you do this. It don't care if it worked before; something may have gotten broken. DO this test once the cam is back in, and let us know.