Tweet
Well, I've finally got around to this issue which was the subject of a recent posting. Here's the deal; it's actually pretty simple:
All 1963-82 Corvettes with STANDARD SUSPENSION used rear shock mount shafts GM #3820929, left side, and GM #3820930, right side. These shock mount shafts are machined from an ASYMETRICAL forging. This is due to the fact that there is an angular "offset" between the longitudinal axis of the shock mount shaft end and the longitudinal axis of the strut rod mount shaft end. Consequently, the unmachined "hub" of the forging has the specific part number for each pice, left side or right side, embossed on the piece and each side can be so-identified. Typical examples of the parts used in PRODUCTION will have the part numbers mentioned seen on the parts. However, in many cases, especially later PRODUCTION due to forging die wear, the numbers may appear to be very lightly embossed and may even be therefore somewhat obscured by the usually thick zinc plating.
All 1963-82 Corvettes with F-40, F-41, or FE-7 heavy duty suspension originally used in PRODUCTION shock mount shafts GM #3829265, left side, and GM #3829266, right side. These shock mount shafts have a very obvious difference in configuration than those shafts described above which were used on standard suspension cars. These shafts were machined from a SYMETRICAL forging. Consequently, the shafts for either side could be machined from the same forging. As a result, the part number embossed on the part is a "dual" part number which is seen as either "3829265-6", "382926566", or "3829265-66". These numbers also may appear very lightly embossed. However, due to the far less number of these pieces manufactured, the forging dies probably remained in better condition and the numbers are usually "sharper".
While the GM #3820929 and 3820930 shafts were used in PRODUCTION for standard suspension 63-82 Corvettes, the GM #3820929 was discontinued from SERVICE in February, 1978 and replaced, for SERVICE, by the GM #3829265. Likewise, the GM #3820930 was discontinued from SERVICE in July, 1978 and replaced, for SERVICE, by the GM #3829266. Both of these replacement parts were, of course, the parts that had been used in PRODUCTION and available in SERVICE since late 1962 for 1963+ Corvettes with HD suspension. So, after these dates, if a replacement shock mount shaft was required for any 1963+ Corvette, only the HD suspension mounts would have been available.
In the mid-90's, or so, another change took place in the SERVICE examples of the GM #3829265 and 3829266 shock mounts. The embossed part numbers disappeared and were replaced by a laser printed part number of the specific number applicable to each side shaft. This style shock mount shafts were SERVICE only---they were never used on a PRODUCTION Corvette----PRODUCTION Corvettes all have the embossed part numbers as described above.
The GM later SERVICE parts with the laser-printed part numbers are, I believe, the exact same pieces sold in reproduction. Configuration-wise, they are the same as the GM #3829265 and 3829266 except that they have neither the embossed part number nor the laser-printed part number. As far as I know, there never has been ANY reproduction of the GM #3820929 and 3820930 shock mounts originally used on the vast majority of 1963-82 Corvettes. These mounts were found on all 1963-82 Corvettes with standard suspension as used in PRODUCTION or available in SERVICE until 1978---that's it; no others exist(ed).
While the GM #3829265 and 3829266 shock mounts and the similarly-configured reproduction pieces will SERVICE all 63-82 Corvette applications perfectly, even aside from the embossed number issue, they are different in configuration than the shock mounts originally used for all standard suspension Corvettes. They can be discerned at a glance.
Attached to this posting are some pictures hi-lighting the differences between the shock mounts. However, I have only posted pictures of NOS examples of the LEFT SIDE mounts (3820929, 3829265 (embossed numbering), and 3829265 (laser-printed numbering). The right side pieces are, obviously, similar but I just didn't feel like pulling those out and photographing them. Also, while I have NOS examples of many different embossed numbering configurations (for the HD mounts) and variations in the embossings (for the standard suspension mounts), I didn't drag those out, either. As usual, though, NONE of these pieces, pictured or not, are for sale.
63-82 Shock Mount Shafts (left side)
All 1963-82 Corvettes with STANDARD SUSPENSION used rear shock mount shafts GM #3820929, left side, and GM #3820930, right side. These shock mount shafts are machined from an ASYMETRICAL forging. This is due to the fact that there is an angular "offset" between the longitudinal axis of the shock mount shaft end and the longitudinal axis of the strut rod mount shaft end. Consequently, the unmachined "hub" of the forging has the specific part number for each pice, left side or right side, embossed on the piece and each side can be so-identified. Typical examples of the parts used in PRODUCTION will have the part numbers mentioned seen on the parts. However, in many cases, especially later PRODUCTION due to forging die wear, the numbers may appear to be very lightly embossed and may even be therefore somewhat obscured by the usually thick zinc plating.
All 1963-82 Corvettes with F-40, F-41, or FE-7 heavy duty suspension originally used in PRODUCTION shock mount shafts GM #3829265, left side, and GM #3829266, right side. These shock mount shafts have a very obvious difference in configuration than those shafts described above which were used on standard suspension cars. These shafts were machined from a SYMETRICAL forging. Consequently, the shafts for either side could be machined from the same forging. As a result, the part number embossed on the part is a "dual" part number which is seen as either "3829265-6", "382926566", or "3829265-66". These numbers also may appear very lightly embossed. However, due to the far less number of these pieces manufactured, the forging dies probably remained in better condition and the numbers are usually "sharper".
While the GM #3820929 and 3820930 shafts were used in PRODUCTION for standard suspension 63-82 Corvettes, the GM #3820929 was discontinued from SERVICE in February, 1978 and replaced, for SERVICE, by the GM #3829265. Likewise, the GM #3820930 was discontinued from SERVICE in July, 1978 and replaced, for SERVICE, by the GM #3829266. Both of these replacement parts were, of course, the parts that had been used in PRODUCTION and available in SERVICE since late 1962 for 1963+ Corvettes with HD suspension. So, after these dates, if a replacement shock mount shaft was required for any 1963+ Corvette, only the HD suspension mounts would have been available.
In the mid-90's, or so, another change took place in the SERVICE examples of the GM #3829265 and 3829266 shock mounts. The embossed part numbers disappeared and were replaced by a laser printed part number of the specific number applicable to each side shaft. This style shock mount shafts were SERVICE only---they were never used on a PRODUCTION Corvette----PRODUCTION Corvettes all have the embossed part numbers as described above.
The GM later SERVICE parts with the laser-printed part numbers are, I believe, the exact same pieces sold in reproduction. Configuration-wise, they are the same as the GM #3829265 and 3829266 except that they have neither the embossed part number nor the laser-printed part number. As far as I know, there never has been ANY reproduction of the GM #3820929 and 3820930 shock mounts originally used on the vast majority of 1963-82 Corvettes. These mounts were found on all 1963-82 Corvettes with standard suspension as used in PRODUCTION or available in SERVICE until 1978---that's it; no others exist(ed).
While the GM #3829265 and 3829266 shock mounts and the similarly-configured reproduction pieces will SERVICE all 63-82 Corvette applications perfectly, even aside from the embossed number issue, they are different in configuration than the shock mounts originally used for all standard suspension Corvettes. They can be discerned at a glance.
Attached to this posting are some pictures hi-lighting the differences between the shock mounts. However, I have only posted pictures of NOS examples of the LEFT SIDE mounts (3820929, 3829265 (embossed numbering), and 3829265 (laser-printed numbering). The right side pieces are, obviously, similar but I just didn't feel like pulling those out and photographing them. Also, while I have NOS examples of many different embossed numbering configurations (for the HD mounts) and variations in the embossings (for the standard suspension mounts), I didn't drag those out, either. As usual, though, NONE of these pieces, pictured or not, are for sale.
63-82 Shock Mount Shafts (left side)
Comment