How consistent are JBLs unit-to-unit?

I have 3 pairs of L80Ts, 2 of which need refoaming, one was refoamed by an owner. I bought one pair, then got one free, then got one really cheap. I intend to keep one pair and upgrade to L80T3 spec, and sell the others. I was thinking of taking a pair of woofers with foam that's just barely starting to crack, (thus I know they haven't been run with the cones out of aligment and rubbing VCs or anything) getting those refoamed at a JBL service center, and putting those in the cosmetically best pair of speakers along with T3 Xovers.

Are there differences in the sound between pairs? I don't really want to take the time to haul all of them out of the basement and drive myself crazy A/B-ing, but I don't want to sell a pair that might not be the best. As long as everything is functioning, are there likely to be significant difference in performance between one unit and the next?

Mine all seem to sound the same within the same model. I have two pair of L80Ts, both now converted to T3 crossovers. Foam 'em yourself. Couldn't be easier!

I currently have 2 pairs of L80Ts. One set looks to have an aftermarket re-foam job (as JBL never made "foam" kits and no authorized service center should tell you otherwise) and the other has a genuine JBL recone job.

I see absolutely no difference in sound between the pairs. L100T vs L80T is quite a different story.