How do you know what the firing order numbers are on an original distributor cap of an OLD 78 Caprice Classic?

If it has a smallblock Chevy the firing order is 1-8-4-3-6-5-7-2.....number one ussuall being one of the front capterminals right behind the carb. start there and go clockwise around the cap. If one plug is off the car will start but run rough...more than that and it wont run.

Acually #1 cyl on the distributor cap , is usally pointed in the general direction of the #1 cyl itself, in that car and most all sb Chevy's excluding the LS generation of GM sb engines, #1 is 1st plug, or cyl, drivers side.