1968 340 timing

Same here not familiar, and means nothing to me.

Yur gonna have to get dirty and find TDC #1cylinder, on compression stroke, and find out exactly where your balancer mark is. You may have to make a new one or install a timing tape.

I agree about most timing lights not working with an MSD while it is Multi-Striking below ~3000 rpm. To check the power-timing,you're gonna have to rev it higher.

I think your right. Its been a while ( 6 years or so ) but I did notice some black marks on the balancer...I think I put there finding TDC. What is timing tape.