John, there are several ways to find TDC.
TDC is generally referred to as the #1 piston being at TDC on the compression stroke, but of course there are 11 other times that one of the pistons is at TDC.
Depending on how accurate you need to be will determine the method.
Some quick and dirty ways are to pull the #1 spark plug and then just barely start the threads again, maybe just 1 turn. Then turn the engine over by hand only. When you hear air rushing out of the sparkplug hole, then you are coming up to TDC on the compression stroke. You can also stick a piece of paper towel in the hole and it will blow out as you rotate the engine to TDC.
If you have the distributor off, then you can look at the rotor, when it points to the #1 wire then you are approaching TDC at compression on #1. You can take out the other 5 plugs, and turn the engine over; when you get a strong resistance you know #1 is approaching TDC on the compression stroke.
After confirmation that you are on the compression stroke, then look on the balancer and find the stamped timing markings for 0 degrees. Slowly rotate the engine until the 0 mark is just below the little tab sticking down next to the crankshaft position sensor.

If you have the valve vover off, you can rotate the engine until the #1 intake valve (opposite the #1 intake manifold runner) opens, and then closes.
Then rotate the engine on up to the 0 mark on the balancer, or you can align the cam marks as you stated.

If you need to be really accurate, you need a piston stop to screw into the sparkplug hole, and a dial indicator wheel on the balancer. But that's a long story. Go to Compcams.com to read a 5 page tutorial on timing and engine.

DG