I'm getting ready to re-install my distributor and I need to know where the #1 cylinder is located on the distributor cap. I've got a 67 Skylark with a 340 4 bbl carb. I have two different diagrams that show two different locations. One is on the right side pointing towards the number 1 cylinder and the other is on the left side pointing towards the number 2 cylinder. Which one is correct?
Right, it doesnt matter where the wires on the cap are...its the direction the rotor is facing. Then line the proper wire on the terminal on the cap that corresponds to the rotor direction.
If the #1 cylinder is indeed at TDC, then as long as the oil pump driveshaft engages the distributor properly and the vaccum advance diaphragm wont hit anything as you set the timing, then it doesnt matter which way the rotor is facing. Typically the vacuum advance is facing between 6 and 9 o'clock as seen from above. Remember the gears are helical and as the distributor gears engage, the rotor will rotate.
There were two different locations depending on build date. But like it has been stated, it doesn't matter where on the cap #1 is as long as you set the rotor correctly, to fire #1 at top dead center. I would locate the #1, on the first tower clockwise from the dwell adjustment window. Then follow the firing order clockwise around the cap 1-8-4-3-6-5-7-2 Then put the cap on the distributor, and mark the location of the #1 tower on the body of the distibutor. Then pull the #1 plug. Cover the hole with your finger, and have someone bump the starter over, until you feel compression on your finger. Look at the mark on the balancer, it should be coming around. Line up the mark with the 0 on the timing tab. Then install the distributor, so that the firing end of the rotor points to the #1 tower. The rotor will turn as you push the distributor home, so you'll have to start with a rotor position that is clockwise of where you want to end up. The vacuum cannister should point to the passenger side corner of the car, and the distributor should fully seat, and mesh with the oil pump drive. This may take a few tries before everything lines up.
