A:Answer Depends on the frequency response of the JBL's and if they are blown or not. If the speaker surrounds are torn, or made of paper, or even the cones made of paper, these pioneers would definitely make a difference! I cannot tell you what they fit into, however, I bought these for a 2013 Camry and 1993 Toyota Previa. So in some locations they are direct fit, and some have to have an adapter, or you have to modify the fit. I hope this helps!
I would replace all speakers in the vehicle, even if only one was blown or they had paper cones or surrounds! My 2002 Camry has a JBL sound system, but the cones are paper.
BB has a vehicle specific fit finder on their website to let you know what speakers fit each vehicle. There is also a web site that has Crutch Field in the name that can tell you what fits.
Hope you find what you want!