We had to replace the Heater Core in our 1987 Firebird Formula, still an original car.
I found the following and hubby installed them in the dash and rear and they were a perfect fit.
Sounds incredibly better, even with the original Delco Cassette Stereo.
(Now I just gatta get him on board with changing out the stereo! HaHa)
Replaced with:
1) KENWOOD Door/Rear Deck Speaker KFC-4675C
4x6 inch 2-way 2-speaker COST: $69.99
Woofer………………….…… 95mm x 153 mm (4x6 inch) Cone
Tweeter………………….….. 25 mm (1 inch) Balanced Dome
Peak Power………………... 60W
Frequency Response….. 50 Hz – 25,000 Hz
Sensitivity……….………….. 90 dB / W at 1 m
Impedance…………………. 4
Net Weight…………………. 760 g (1.7 lb) / Pair
2) KENWOOD Flush Mount Speaker KFC-6995PS
6x9 inch 5-way 2-speaker COST: $99.99
125Watts RMS Power
Cutout Diameter………… 5-7/8 x 8-9/16 Oval (3-1/16 in. Depth)
Woofer………………….…… 153mm x 229 mm (6x9 inch) Cone
Midrange……………………. 70 mm (2-3/4 in.) Cone
Tweeter………………….….. 20 mm (13/16 in.) Balanced Dome
*Super Tweeter……..….. 12 mm (1/2 in.) Dome
*Super Tweeter……..….. 10 mm (3/8 in.) Ceramic
Peak Power………………... 650W
Frequency Response….. 60 Hz – 20,000 Hz
Sensitivity……….………….. 88 dB / W at 1 m
Impedance…………………. 4
Net Weight…………………. 000 g (0.0 lb) / Pair