I have T-tops in my 71-72 SG they both measure at 7.5 ohms exactly. The have a very small black sticker with the parent number. I also have T-tops in my 74 LP Standard. I have never looked at he bottom of them. Both sets of T-tops sound brighter and more trebly than the Burstbucker 1&2 in my R9. I actually like the T-tops better for most applications. They are more well behaved than the BBs but still rock out through a cranked amp. More articulate and comparable sustain. The 74 LP has the sandwiched body (a wafer of maple between the layers of mahogany) and a 3 piece neck, so I would expect it to be more trebly than the R9 regardless of the pick ups. What I can say is that through out the 70's and early 80's that 74 LP was noted for it's full and powerful tone as compared to any other electric guitar by those that heard it. In the mid-80's I put a Dimarzio Superdistortion in the bridge of the SG, after about a year I switched back to that 7.5 ohm T-top. It sounded great through both the clean Twin Reverb and cranked Super Lead compared to the Dimarzio hot pick-up. I am not sure what the big deal is about the T-tops because there are so many excellent pick ups out there today. They are good but not really better than the good quality PAF clones out there. There is a lesson here it would be that hotter or higher resistance pick-ups are not necessary to have a great distorted tone and moderate (7.5 ohm) winds generally sound better clean.