No. 1 wire position on distributor cap
 

What is the quickest way to find where no. 1 plug wire goes on a 502 hei distributor cap? I marked the wires and put a mark on the cap for no.1 and then removed the wires and brought the cap to the work bench to check it out. While cleaning the contacts I must have rubbed the mark of from the cap. Any good ideas? I trust you guy's. Thanks

not sure about a 502 hei but on my Merc sbc caps the numbers are stamped right on the cap

Pull the number 1 sparkplug out. (looking at front of motor the front one on the right) Stick your finger in the sparkplug hole & tap the starter. When you finger blows out you are at/close to TDC. Look where the rotor is facing & that is where the number one plug wire goes.

Like Turbojack said, find TDC on #1 cyl first.
Most manuals recommend that the rotor be positioned to physically point at the #1 cylinder, sometimes the cap is marked which tower is to be #1.
In reality it doesn't matter what direction it's pointing as long as you know which tower is #1.

I'm not really sure that you are getting the answer to the question you asked here. On a standard (L.H.) rotation wiring the #1 terminal will usually be just left of the forward most point on the cap when installed and viewed from the flywheel end. (rear) the alignment notch in the bottom lit of the cap is between #5 and #7 terminals. Count around in proper firing order from the notch (1-8-4-3-6-5-7-2 for std. rot.) and you have where Merc puts #1. Hope this is what you wanted to know. --- Jer