Picture of number 1 on distributor cap - 1984 Buick Regal

I don't like to post pictures of distributor caps, too many times they are wrong. Just my opinion. If you put number 1 piston on tdc of compression stroke then look at the dist rotor, it should be leading into the number one spark plug tower, in the proper direction of rotation, counter clockwise. then you follow the firing order around the cap. I did mark number 1 in the diagram, found that in my database, I can't be positive it is correct?

See if the spark plug wire numbers are visible where they connect to the distributor cap. find the #1 mark on the distributor cap and you will be able to see the firing order. The firing order may be in raised numbers on the intake manifold too.

For this you have to determine when the #1 cylinder is at TDC (Top Dead Center) - when it would be firing. Take the distributor cap off and look at the rotor - it would be pointing at the #1 spark plug wire on the distributor. The wires would be connected it order around the distributor cap starting at 1. The sequence is 1-8-4-3-6-5-7-2 in a clockwise fashion.

I assume its a V8 and probably a 5.0L

5.0= 1-5-4-2-6-3-7-8 firing order

5.0 HO and 351 Windsor share 1-3-7-2-6-5-4-8 firing order

Cylinder numbering:

When looking into the engine bay the number one cylinder should be on your left hand side (left bank) at the front of the engine. The number eight cylinder is on the rear right (right bank) up against the firewall.

Firewall
4 8
3 7
2 6
1 5
Front bumper

distributer turns counter clockwize (#1 should be labelled on cap)

If you look at the distributor cap from the wires side carefully, you would find either a line mark on one of the outer side of four holes (where the spark plug wires are inserted) or the numbers printed on the top of distributor cap (1,3,4,2). Fix one end of the longest high tension plug wire into number 1 hole or the one marked with a line mark on the distributor cap and the other end on spark plug number 1 (the number 1 plug is toward the pulleys and the belts side, then No 2, No 3 and No 4). While standing in front of right wheel you will see the distributor cap in front of you. The rotor moves clock wise. After you fix the 1st cord, next comes number 3 plug wire. Insert one end of the cord into the next to 1 on the right hand side and press the other side of the cord on spark plug number 3. Next to 3 is the cord number 4 and the last one is number 2.

15426378

GET A PIECE PAPER DRAW A LARGE CIRCLE TOP UPPER HALF CIRCLE LEFT TO RIGHT WRITE NUMBERS 1 AND 3 BOTTOM HALF CIRCLE LEFT TO RIGHT RIGHT NUMBERS 2 AND 4 THAT YOUR DISTRIBUTOR SPARK PLUGS WIRES LOCATION.STANDING ON SIDE OF ENGINE WHERE DISTRIBUTOR IS LOOKING DOWN AT DISTRIBUTOR 1 AND 3 FIRST TWO SPARK PLUGS TERMINALS NEXT TO ENGINE. AND 2 AND 4 SPARK PLUGS TERMINAL ON CAP FACING YOU. THIS IS CYLINDERS LOCATIONS STANDING IN FRONT OF ENGINE.RUN WIRES FROM DISTRIBUTOR CAP TO PLUGS TO THE ENGINE SPARK PLUGS.

here is the distributor picture

V8s are 18436572 going clockwise number 1 should be marked on cap or closest tower facing you standing at the rad