If it's still points ignition, that would require some filtering electronics. If it's electronic ignition, just input into a hall sensor configured trigger, select coil type for Trigger Type, number of teeth of full engine cycle will be the number of cylinders. You'll have to play with the timing light to enter the other parameters, but this is a common setup. BTW, if it's points ignition now, I'd insist the customer upgrade to electronic ignition. I've done that in every distributor with points I come across and have never looked back.