Would you mix these plugs?

[austinrick]

I received these plugs from two different vendors; 2 of the left plug, 4 of the right. Both labeled Autolite APP104.
The little electrodes are different, but I don't know how much difference that makes in the engine (3.0L in a '93 XLT)
Would you use this combination of designs?

 

[austinrick]

I finally got Autolite tech support on the phone and the agent knew exactly what I was trying to describe.

He assures me that, for all practical purposes, the two are identical and I can mix them in an engine, no prob.

The left plug is an older style, the right one newer, but they fire exactly the same, same heat range, spark, etc., etc., so I'm going with these.

 

[pentode]

It's not "ideal" in a perfect world, especially if you have a certain level of OCD like me. Having seen how well the 3.0 runs on awful plugs though, I would bet it will be a long time before you'll ever notice any issues.

 

[Curious Hound]

Without the manufacturer's input, I would have said NO.

 

[pentode]

I should have made it clearer that I would always prefer matched plugs. I would only run those if getting a matched set was going to be a pain, which for some reason I assumed it was.