Am going to buy new plugs and wires for the rebuild. I was researching and found a bunch of different choices.

I need some direction.

Rebuild is a stock rebuild. I bought a Petronics 3 to replace points, also bought the recommended higher voltage coil for the Petronics.

So, do I use just the stock copper plugs? or do I step up to a better plug?

bill v

I use a set of stock A/C Delcos, just set the gap a little wider than normal for the electronic ignition. 0.040 to 0.045 is a good place to start.

X2 on what Jeff said....... that worked for me when I had the same set up in my car.

When you guys say stock, i would think that means copper not titanium or platinum etc, correct?

I been trying to find a chart on Ac delco plugs but can't find a list. I wanted to see a list and figure out the differences. have seen comments about using a "hotter" plug etc, trying to understand it.

Thanks bill v

Don't get caught up in all the spark plug hype, Rock Auto has the R45S plugs that will work just fine in your application. Other fancy expensive plugs weren't designed for these engines, stick with what the engineers picked.

http://www.rockauto.com/en/moreinfo.php?pk=90010&cc=1249264&jsn=402

Thanks guys,

couple questions:

Whats the difference between R-45s and R-46s plugs?

And a general knowledge question:

Dr, in the rock auto page you posted. They talked about copper core and the performance of heat transfer to the plug tip. So, does that mean that heat generated by the spark sets off the combustion or is it the electrical charge that does it?

I've heard people say "use a hotter plug" I wondered what that meant.

Thanks bill v

R46S is one heat range "hotter"

Hotter refers to how well the spark plug transfers heat out of the core.

Colder plugs would be used for engines with higher cylinder pressures, ie compression, turbos, superchargers, they are more susceptible to detonation.

In a gas engine, the spark always ignites the fuel/air mixture, unless you have detonation issues caused by timing or excessive carbon build up in the cylinders.

Although this is from NGK, the basic theory is the same.

https://www.ngksparkplugs.com/about-ngk/tech-talk/spark-plug-basics

Thanks for the link Dr. thats perfect to learn something.

question though. Why open the gap To .040-45 ? is that because of the newer coil, maybe higher voltage? heat?

bill v

Large gaps .040-.045 is ok if you have a decent electronic ignition system that has some power. For a factory points set up .032-.035 is maximum. A larger gap builds more resistance on the factory points system.
I have been using the r44-r45 heat range on all these engines. You wouldn't use a r46 unless you have a worn out oil burning engine that you just want it to make it down the road.