Bridge EJ seems to be nearly identical specs and EQ of neck AC according to Dimarzio website, aside from being brighter, so was wondering how both would work together, but neck EJ probably does sound like a natural fit.
The EJs were designed to sound like Filtertrons but in a humbucker route. The neck and bridge are the same basic recipe, just calibrated for each respective position. Personally, I would not look to the EJ Custom if I wanted the sound of a full-size humbucker, at least not in the bridge position. If you’re happy with the Air Classic Neck in the bridge I would stick with that.
It was mentioned that a 1M tone pot can be useful in getting more brightness out of a pickup. Choosing a smaller tone cap can also make a marked difference, even with a 500k pot turned all the way up, I would try 15nF or 10nF.
I tried searching more for what Filtertrons generally sound like, and I must say, I think I like this direction more. I've never been happy with any traditional humbucker in the neck, and I tried plenty of them. So if the EJ Custom sounds closer to a single coil than PAF, I'd probably like that more.
I don't know. I have the Air Classic set in 2 guitars, one Les Paul and one Paul Gilbert Ibanez RG. That humbucker set is very bright in both guitars, rivaling the single coils in my Strat.
Have you checked the pot values in your guitar with a multimeter?
Would you say then that even Air Classic Bridge is close enough to single coil, especially overwound models like Heavy Blues 2?