Pickup rings

[rdamaral]

Flat rings (like, perfectly flat with no angle whatsoever) will leave your inner bridge pickup coil closer to the strings than the outer one. Granted it won't be much, but it'll be enough to affect the response of the pickup.
You need at least some angle to match the string angle.

When you ordered them from DiMarzio, did you expressly state you wanted short flat-bottom rings?

No I didn't. I'm not blaming Dimarzio for anything, I ordered the wrong ones initially. The shorter of the LP rings might work with a little shaving.

As far as the flat ones go, that's what came equipped on the white ghost flames one, so I don't see a problem with using the low profile flat ones.