Setting Total Timing with MSD Box

[72cudaman]

So after sitting for a long time, I've got my 72 'Cuda running.  It came original with a 340, but it was replaced a moderately built 440.  The motor was built and dropped in the car shortly before I got it, I don't even know if they put enough miles on it to justify an oil change.  Long story short, I got the motor running pretty quickly, and it's actually running fairly good considering that it was sitting for a while, but the idle is a bit lumpy.  I wanted to check the timing, in particular, I wanted to check the total timing, but the car has an MSD box model 6440 (might be a super old one), and I've read that you can't (reliably) use a dial-type timing light on a car with MSD.

This may be a dumb question, but how can I check total advance without a dial-type light?

[Bullitt-]

I'd start with timing tape on the harmonic balancer, remove & plug the vacuum advance hose.
Then follow brother CP's how to  http://www.cuda-challenger.com/cc/index.php?topic=4430.msg33565#msg33565

[Chryco Psycho]

AS above I just time by ear , no light needed

[CudamanTom]

AS above I just time by ear , no light needed

 
I tried it with a light but had better results doing it by ear myself.
Not being a stock engine, I didn't go to the light.