It was either JL or JBL, can't remember. Found this out when trying to put in a factory CD in my Cougar. Ford and the vendor both told me it wasn't worth the money, and figure be the same for the speakers.
If all else fails get a bigger hammer!
93 SC Tbird
MPII w/ Plenum,90mm MAF, 85mm TB, 40# Injectors, 255 lph FP, Double IC w/fan, SCT Chip (Tuned by Jerry),3/4" Raised Top, F52-TT TC, SilverFox AOD 550, SPT-R VB
96 1/2 XR7 Sold and Salvaged
93 5.0 Tbird