http://www.crankshaftcoalition.com/wiki/Determining_top_dead_center
Forget about the degree wheel in the article, (unless you have one and want to be maticilous, like me), we're just using it to show you how this can be done.
IF you have a length of tape marked in degrees counting down to Zero and then going back up, you can put the -0- where the slash is across the edge of the balancer.
IF your outter ring hasn't spun, that slash, the origional TDC line SHOULD be accurate.
What I would do is lay the Timing Tape over a roll of masking tape, make marks to about 30 Degree's on either side of the -0-. Line the piece masking tape around the edge of the balancer, put in your piston stop.
If you don't have a pointer on your timing cover, make one out of a piece of coathanger or old welding rod....and fasten it under one of your timing cover bolts or studs.
Rotate the motor over slowly until you touch the stop. Feel for it, slowly. Once you hit the stop, look where your pointer on the timing cover is. Make a mark there. Now, rotate the crankshaft back in the opposite direction. When you hit the stop, make a mark.
Now, it your HB is in good shape, those numbers should match X amount of degrees on either side of the slash timing mark.
Clean the HB and put your tape on so that 1/2 way between those numbers is -0- on your new timing tape.
A word of advise, wire brush that HB good, wipe the outside down with a little acetone on a rag, before you put that new tape on. Because of the centrif. force, oil/fuel, contaminants, etc., if you don't clean it good, you won't have it for long. After you clean it and paint it (After we get the motor to where its not running hot), spray a protective clear coat over it....
Now, once you have it on, time the motor and tell us....