May 2017

Time to figure out the stereo.

First I did some research into what was originally available for B body radios.
This info may not be as complete / thorough as my E body radio post, but it's a good starting point for anyone looking for info though, and maybe it will help point someone in the right direction.

B Body Radio Options 1968-1970 & 1971-1974

In 68-70 B bodies Only the AM 8-track cars had a 3 speaker dash (with crossover box and harness)
The AM 8-track was the only Stereo radio available. AM & AM/FM radios in 68-70 B bodies were Mono.
Some 68-70 cars have package trays with symmetrical speaker holes, while most have asymmetrical speaker holes. The difference was do to different vendors supplying the part.
68-70 R31 is the rear speaker option.
68-70 never had dual rear speakers, they had an optional single rear speaker.
That rear speaker is a 5 x 7 speaker on the drivers side.
The passenger side hole was only used for an optional defogger.
The defogger was designed to fit in 6 x 9 speaker holes, so that is why the 68-70 B body defogger intake opening looks like a 6 x 9 speaker hole.
Since dual rear speakers were not available, these cars never had an adapter for dual speakers with defogger.
In 68 the rear speaker fader was next to the radio in the faceplate.
in 69 & 70 the rear speaker fader was on the bottom of the dash frame, to the left of the ashtray.
Stereo radios with a rear speaker used a dual pot fader, while mono radios with a rear speaker used a single pot fader.



71-74 B bodies never had a 3 speaker dash, not even on cars with a Stereo radio. Instead, a Stereo radio came with a single dash speaker and a drivers rear speaker.

71-72 B bodies could have...
mono AM single dash speaker
mono AM single dash speaker + drivers rear speaker
mono AM single dash speaker with cassette player (only 71-72, not a listed option in 73-74)
mono AM single dash speaker with cassette player + drivers rear speaker (only 71-72, not a listed option in 73-74)
Stereo AM/FM single dash speaker + drivers rear speaker
Stereo AM/FM single dash speaker with cassette player + drivers rear speaker
A Microphone is listed as being optional only with cassette players, and only for 1971. (likely available over the counter for other years)
Defogger was optional and used the passenger side package tray hole as an intake, same as in previous years.
The package tray is missing a provision for mounting the dual speaker with defogger adapter, these cars never had an adapter for dual speakers with defogger.

73-74 B bodies could have...
mono AM single dash speaker
mono AM single dash speaker + drivers rear speaker
mono AM/FM single dash speaker (new for 73-74)
mono AM/FM single dash speaker + drivers rear speaker (new for 73-74)
Stereo AM/FM single dash speaker + drivers rear speaker
Stereo AM/FM single dash speaker with cassette player + drivers rear speaker (only 71-73, not a listed option in 74)
Defogger was optional and used the passenger side package tray hole as an intake, same as in previous years.
The package tray is missing a provision for mounting the dual speaker with defogger adapter, these cars never had an adapter for dual speakers with defogger.


The adapter for dual speakers with a defogger was only used on E bodies & C bodies. (same part on both cars)


Original speakers were 8 ohm
You never want to run 4 ohm total impedance speakers with these old original radios. It will burn up the radios output transformer over time.

Modern aftermarket radios are designed to handle modern 4 ohm speakers. (you could use 8 ohm speakers with a modern radio, but it would be quiet)

The new reproduction B body radios have modern internals and can handle 4 or 8 ohm speakers.

Turnswitch.com has an excellent selection of 4 ohm & 8 ohm speakers that are designed to fit classic cars without cutting your car or dash. They accomplish this by using smaller super magnets like inside computers, instead of using larger less powerful ceramic magnets that are typically found on aftermarket speakers.

Having original speakers reconed isn't a great option if you plan to actually listen to the radio because the old magnet will never be as good as it used to be.



I decided to use a Retro Radio power antenna, which I modified a bit. It comes with a flexible portion in between the mast and the motor. I removed this flexible portion.

Though this car was originally a Stereo 8-track car with the 3 speaker dash, I decided to go with a reproduction 1970 AM/FM with all modern internals. It has Bluetooth and an auxiliary input on the back for my MP3 player.
The 1970 AM/FM B body radio is a very desirable one year only radio, and I'll be glad to use my 3 speaker dash with the modern internals.
Antique Automobile Radio is the manufacturer. http://www.radiosforoldcars.com/whoF.htm

For Speakers, I went to Turnswitch.com and ordered a pair of the 3.5 inch square 8 ohm speakers for the stereo dash locations, and a 4x10 Mopar B body Stereo High Output 8 ohm for the dash center (it's a bracket that holds two 8 ohm round speakers in the original 4x10 location, without interfering with any of the heater cables under the dash).
This gives me four 8 ohm dash speakers, that I've wired in parallel so that the left pair is a 4 ohm load, and the right pair is a 4 ohm load. The reproduction radio has modern internals which can handle a 4 ohm load, so this should sound great!
The 3.5 inch square outboard speakers need a bass blocker installed in line with the speaker wire so that they don't distort from low bass notes. The center dash speakers can handle the low notes and don't need the bass blockers.
I also ordered a pair of the SX69 coaxial 6x9 oval speakers, which will mount under the package tray just fine without any cutting or drilling.

Wiring Diagram pictured below.