380 sel no start
 

I am going to look at an '83 today that supposedly has electrical problems. The guy said the car just shut off on him and wouldn't restart. I plan on trying to turn the motor over and look at the cam through the valve cover to see if it is spinning.
The tension rails could have broke and the chain could have jumped a tooth, right? So this means the cam would still spin as you try to start the car.

Would a compression test be more definative?

What should I do to rule out timing chains without taking anything apart. The car is still in the guys driveway and my tools I have with me are limited.

Thanks,
Paul