The 1968 Corvette used the AM/FM Push Button receiver with Unit No.* 987453 for the small block 327, while the Unit No. 987464 for the big block 427.1 While the AC Delco Parts sticker might have peeled off from 40+ years of wear and tear, a 1968 Corvette Radio can still be distinguishable by the word “Stereo” in cursive or script writing (if Stereo equipped).2 It is also noted that the lettering on the front face of the radio lights up in green.
The 1969 also had its own radio unit, with part number 993642.3 While this AM/FM unit also read “stereo” on the front face, it was written in capital and block lettering. The 1969 also retained the green backlight to the lettering.2
The 1970-1971 came out with two different part numbers for the radio units. One was equipped with stereo (PN 7303211), and one was not (PN 7302721).4 Both radios had the script “Delco” on the front in script writing. The stereo unit, upon receiving FM stereo, will light up the capital, blocked “STEREO” lettering. The 1970-1971 units were the last years to have green backlight as well.5 One thing to note also; in order to distinguish the 1970-1971 mono radio from the 1972-1973 is on the latter one, there is a circular cut out that exposes the capacitor (see Image 1.1).
The 1972-1973 Radio for the Corvette was the first one to come out with white-backlit lettering. It is also in the same radio where AC Delco changed out the word “STEREO” to a bright orange glowing dot on the right upper corner of the face, to show stereo reception.5 This radio uses part number uses 7937581, while the mono uses part number 7937571. Lastly, AC Delco started manufacturing 72-73 with the circular cut out on the back that exposes the capacitor (see Images 1.1 – 1.4). On June of 1973, the part no. 7937581 (Stereo) ceased in production and was replaced by part number 9341341.6
The 1974 Corvette had a one-year production of the AM/FM Stereo unit with part number 9341341. Because of its one-year-only production, it is considered rare. Production of this unit ceased on October 1974.7 The mono AM/FM receiver (PN 7937571), on the other hand, was used until 19748 and is found to be common.
As the first production of the 1975 Corvette began in October 1974,9 so did the production of its stereo radio unit with part number 934661.7 This part number was used all the way to the 1976 Corvettes. The mono radio for the 1975-1976 uses the part number 9344651.10
1977 was the first year for using the generic Delco line of radios. Three units were offered, an AM/FM mono, an AM/FM Stereo and an AM/FM Stereo 8-track. For the 1977 year, all push buttons were black plastic. The 1977 8-track unit did not have a tape eject button. In 1978 the push buttons were chrome and the 5th button over was also the eject button for the tape.
Also, 77 used earlier style connectors and in 1978, connectors changed.
1977 AM/FM Mono Model # 70HFP1
1977 AM/FM Stereo Model # 70HFM1
1977 AM/FM 8-Track Model # 70HFMT1
Part # for AM/FM 8-Track is 70HFMT1 - 4898160
Part # for AM/FM Mono is 70HFP1 - 9345270
Part # for AM/FM Stereo is 70HFM1 – 7897770
AM/FM Stereo used P/N 789849011
AM/FM Mono uses P/N 1600180112
AM/FM Stereo uses P/N 16009461
*Unit No. and Part No. used interchangeably in the Chevy Radio Parts Catalog