I never thought I would have to asked something like this but here goes. What is the best spark plug for a performance FE. I have always used autolites but have heard they suck now. Every time I search it comes up with AP 45's. When I check cross references it keeps circling around different heat ranges. I have a stroker FE 427 high riser 12:1 with cast iron heads. Because of my mallory ignition and low resistance wires I want to make sure I get the resistor type. BF-32, autolite 44 are no longer but I see them on ebay way over priced. Does any one know of a new plug for my application? What about champion rf9yc the rf11yc might be to hot.

Thanks

 

If memory serves, the Champion plug crossreferenced for my 360 was an RF11. I used to use RF10s, and used them in my hi-po built 390 (11:1) with no issues.

The RF9 might be a bit too cold, or just right. Depending on cam, gas, timing, etc, it's up to you.

But yet, an RF9 or 10 would be the right thing. Just make sure the length of the plug tip is OK, compared to what you are already running.

 

I'd install insert to use the smaller plugs, lot more to choose from.

 

I always bought Champion sparkplugs, but had some trouble with them a year or so ago, and have switched. I tried Autolite 45s, and they seem to work just fine.

I had a new Champion plug go dead on me on the subsequent test drive. It may have been cross-fire induced, so I can't say for certain it was the plug, however, it caused me to take a close look at Champion plugs.

The problem with Champion appears to be a lack of Quality Control, and I suspect it may be because they are now made in China.

Here's a pic of two "identical" plugs. Note the different lengths of the porcelin insulator nose:



Here's another where the threads were made wrong (no, I didn't cross-thread them):



So at this point, I'd recommend staying away from Champion and use Autolite's, although I have no thoughts on the heat range other than the 45s seem to work well in my engine.

...or you could use these



Trivia Note: AC sparkplugs get their name from Albert Champion. Technically focused, he was unwittingly forced out of his own company (Champion) and so started up again (I think with Delco) to make the AC plug.

 

I like the old Autolite 45's, IF you can still find the "Made In USA" Autolites.

The quality of the new China/Mexico made Autolites isn't that great.

 

Agree. I also still source the old BF-32's when the price is right.

 

Thanks for all the replies. I was wondering what compression, you guys that like the 45's, are running. I was told the new china autolites suck. I was also told that champions got a bad name years ago when they did not keep up with the newer fuels that were coming out, but now they are fine. Who knows what rumors are right I just wish I could get some old autolite 44's ,45's, or bf-32 with out the price tags. So here is my plan right or wrong. I am going to try the champion rf9yc because of their heat range and if they don't work right I will put the china autolite 45's. I will update later on next month because the engine is still out. Does anyone suggest the wix racing filter for a FE that is only ran 4 or 5 times a year? They are supposed to flow better and work for about 1000 miles. The one I am looking at has the relief and anti-drain back valves.

Thanks