Upgrading the drivers on my old Definititive bp8

These where bought back in the mid 90's and was wondering if anyone has experience with upgradng the drivers on these. What brand and model do you recommend? I wouldn't need direct drop in, so if I need to router some material out to get some drivers that will make these speakers shine, I'm all over it.
Why wouldnt you want to call Def Tech and replace with proper drivers if at all possible??, if its your goal to potentially change the sound of a decent speaker to something you dont like and make them worthless then go your route but I think calling Def Tech is best advice anyone can give. Even if they by chance dont support that model now they may offer what speakers will sound good.
Why would you want to upgrade the drivers these were only $800 speakers ? And I could just about bet you will pay at least half of that for new drivers. You want to upgrade, upgrade to the BP 30's or the discontinued BP20's. DF's are pretty decent, I bought a the BP8's myself around the same time and later the BP10b. Anybody that knows, DF rival speakers costing twice as much.
if you want better speakers, sell the def's and buy something else. I could go into all the reasons it is not a good idea but pretty much there is a 100% chance that anything you 'drop in' will give you worse sound regardless of driver cost.