In 1991 at Carlisle I happened to arrive about 6am, as one vendor was unloading several boxes of mopar radios. He had 3 70B body am/fm's and I bought all of them for $120. I kept 2 for restorations and sold one on ebay for $600 a couple years ago.

It is a one year only part as mentioned. I've seen B body cars with A body am/fm's which will fit somewhat but have a different faceplate/dial arrangement.