small block timing

:bananasmi Any body know the right way to check timing for a 1972 small block chevy? I have a standard timing light but do not know exactly how to use. I found timing lines but they are very rusty. Is there supposed to be a reference line on this?

there is a line in the harmonic balancer and you should have a timing tab on your timing cover, the
big notch in the timing tab is 0, you can set the timing to 0 but i would suggest 4 derees, this is done easier with a timing advance timing light