70 Duster keeps shutting off

My 1970 318 Duster keeps shutting down. It has a MSD 6A and MSD coil. It ran fine for over
3000 miles and then started shutting off. I have replaced the coil and its not fuel. Could it be the MSD box itself. I have heard that you can eliminate the balast resistor with that. It will shut down and there is no dash light then the oil pressure sensor light will come back on and it will start. Im not sure where to start looking.
Any advice would be greatly appreciated.:violent1: