i have a 72 f-250 4x4 with a 4 speed manual transmission and a 390 ci engine. today it failed to start, acting like it was not getting any spark. So when i pulled the distriburtor cap, i noticed the points was completely closed. so when i was readjusting them, i noticed there was a hole in both pieces where they come together, when the engine is running.
how would i know when they are due to be replaced?
thank you for your time

 

I'd say if there is a "hole" in the points it is probably time to replace them and the condenser.

You should set the gap when the engine is at TDC and the points are open via a high spot on the internal distributor cam.

The distributor point gap on that 390 should be 0.017". That should produce a dwell angle from 26 to 30 degrees at idle, with 28 degrees being the target.

After you get the dwell angle right, then you can adjust the initial timing to about 6 degrees BTDC.

 

That is what you will find if they were on the "closed" portion of the distributor lobe.

 

Some point contacts are donut-shaped with a hole in the center to cool them. Don't be alarmed but replace them along with the condenser. Make sure you clean and scuff the distributor plate for a good ground.

 

don't forget to put a light coating of dielectric grease on the distributer cam lobes,and recheck the point gap after you've run it awhile.

 

ProjectDagger,if you can afford to do a small upgrade a Petronix- ignition is a great upgrade.I got tired of the points on my trucks always needing to be reset to get good performance and fuel mileage.Now my plugs last three times longer and I only have to replace the cap,wires,plugs and rotor when they are at their service limit.My trucks start easier,run better and cost me less to keep tuned up.I have never had to reset the Petronix since I installed them.Some members have had trouble with them so I would do a search and decide for yourself.
"bowties in the rearview mirror"

 

i've thought about the petronix for the distriburtor. but my truck only gets used a few times a month. after i get the body restored i may do some upgrades. i'm gonna get some new spark plugs for it also. the previous owner had a cold set in there. so i'm just gonna go ahead and give it a proper tune up.
i usually run champion spark plugs in my fords. but may i ask what would you recommend?

 

Cool, learned something new.

 

Only the fixed side has the hole. The Petronix is the thing to get. No more adjusting, ever.

 

I put a Petronix on my 390, no problems.

 

Do yourself a favor...GO to Electronic IGNITION. I did recently and the truck is like new.
A Pertronix will run you $90, and be sure to test your coil...you'll need a minimum 1.5 ohms.
Pertronix also make a good coil called a "Flamethrower". Obviously, run your series of checks to eliminate any other problems, but you'll be happy you went Electronic mate.