Hello. I did search this question, for days and days over weeks and weeks. I read what felt like dozens upon dozens of conversations about this but never found reliable, practical info. So maybe this will not only help me, but anyone who follows in the future. I've got a 1992 MIJ Ibanez SR800 (4 string) with the AFR active P/J pickups. I like the body and neck but really dislike the sound. (Lots of threads about that.) I've adjusted pickup height, changed the battery, adjusted the tone, got new strings, etc, but in the end I thought it would be a fun project to turn it into a passive bass (like my other bass). The problem has been finding pickups to fit in the cavities. I guess I was naive to think that "any P/J set" would fit the vast majority of P/J basses without significant modification. I play heavy music, fingerstyle, mostly doom, sludge, and black metal. I like that full low end, growl, aggressive, and I'm tuned BEAD. (ha ha, I like passive aggressive.) I'm not fond of the more modern metal sound that can be very thin and a lot of upper register, and I'm not fond of trying to dial in a tone on the guitar using active pickups. I'd rather dime the Volume and Tone, Blend 50/50, and be done. After researching which passive pickups might have the sound I want, I decided that the hotter (as opposed to vintage) pickups probably seemed right, and it seemed like Alinco 5 was often recommended. I ended up buying the Seymour Duncan Quarter Pound P/J set. If you can already guess what happened, please keep reading, you are exactly who I need help from. (If you think I'm choosing the wrong pickups for that kind of sound, please let me know that as well.) Of course I also bought a new Volume/Blend/Tone passive harness, from Best Bass Gear. It turns out the Quarter Pound pickups are the tiniest bit too large for the pickup cavities! Like maybe 1/32" too large (although the screw holes seem to line up). They simply will not fit in the cavities, period. I've read many threads where apparently people are swapping their SR-X00 pickups with QPs, and they're not saying anything about having to enlarge cavities or hammer them in with a mallet. I did not expect there to be a problem. So now I don't understand if the cavity size has changed over the years, if my SR800 is somehow unusual or out of spec, or why exactly I haven't found a single thread that said the QP's are too large for the SR800. The best measuring device I have is a cheap guitar-setup ruler, the kind you use to set string height and pickup height, etc... the kind of accuracy you can get for $9. So probably not all that accurate. When I measure the QPs and compare my findings to their published dimensions, they seem to match, so I feel like it's accurate "enough". Yet I can't seem to find new passive pickups that match the measurements I'm getting of my old AFR pickups. (My measurements will be posted at the end.) It would be far better of course if I could find actual factory dimensions of the AFR P/Js, but I can't find that info anywhere. So there is my dilemma, I want to turn this active SR800 into a passive P/J bass with a full heavy aggressive metal tone, without having to resort to active. Some things that might help me... #1 - Does anyone know the factory spec measurements of the 1992 AFR P/J pickups, so I can compare those with other manufacturers without relying on my amateur measurements? #2 - Did anyone else have trouble putting QP's in their SR800? Or I guess, did anyone have no problem at all? Why is mine not fitting? I can't find any threads that said the QPs won't fit in the SR800. #3 - Anyone know of a chart (for example) where you could look for your bass and its year, then go across the columns to see a bunch of pickups that are designed to fit correctly? (Or, for lack of a better term, is there a "size" of P/J that will fit, so I can search based on that?) #4 - Are any of you connoisseurs of the 1990s SR800s and the replacement pickup possibilities that might work, who might read this and think "this guy needs to get pickup set XYZ, they'll fit perfectly and have tons of full metal tone"? Thanks for any help. I'm pretty frustrated right now. For what it is worth, my amateur measurements of the 1992 AFR pickups, to the nearest 1/32nd of an inch, are as follows... Neck PUs = 2 & 3/16 x 1 & 1/16 (body), with 2 & 3/8 between the screw holes Bridge PU = 3 & 11/16 x 11/16 (body), too complicated to describe the holes, LOL I have no doubt that the factory specs would certainly be more precise, probably decimals that do not correspond to 1/32nd of an inch, and for all I know they're metric. But that's what I get using my little ruler.