I assume the passive pickups you're using are the one's you've referenced above? Did you leave the controls stock (V, blend, T, T) or do something different there too? Result was more what, more the classic T-Bird sound?
Yes, a pair of 9.2kΩ chromes and surrounds from EY Guitar Parts - available via eBay or direct from their website. I removed 2 pots completely and have V-V only (can't remember having rolled off the tone on any bass ever).
These pickups are actually from the factory that supplies a famous guitar maker, formerly of Kalamazoo MI and more recently resident in Nashville TN. So yes, they are closer to a classic TBird sound than the stock pups. You may get even better results from Thunderbucker Ranch or another custom builder, but the EYs are as spendy as I want to be with a $300 bass.
UPDATE: photo added to illustrate pot/knob arrangement.
Last edited: