340 balancer timing marks

Not sure why you'd believe that. Very very simple. It is called a piston stop. I first learned to use one about 1971. Back then I used to find a disturbing no. of Ford 352/ 390s had slipped the balancer and impossible to otherwise set the timing for tune up

If you have an aftermarket wheel, degreed on the wheel for the pass side, all you need is the TDC point. You can make a tab, use a piston stop with say, masking tape to confirm the correct position, then scribe and paint the TDC marker.
I should have said " LACK of verification"