'58 Ignition Shielding Bolts

[Ted S.]

I know during judging that they indicated that the three bolts holding the ignition shielding top in place were hex head. In looking at the AIMs it does show the hex bolts but it also shows revisions to the bolt dated 10/2/57. Take a look at the document dated 12/17/57 showing the wingnut bolts being used on the shielding.

Did the '58s use the wingnuts verses the hex bolts? Were the wingnut type bolts used in '57?

This is from part "3752374 - Radio Ignition Shielding and Adapter Installation Instructions - Corvette"

Thanks, Ted

[Frank P.]

Re: '58 Ignition Shielding Bolts

For 1958 the judges look for chrome plated hex head bolts with chrome plated split lock washers.

[Ted S.]

Re: '58 Ignition Shielding Bolts

For 1958 the judges look for chrome plated hex head bolts with chrome plated split lock washers.

Frank, potentially neither the AIM nor this GM document support that. If you look at the AIM drawing notes, the bolt was revised in October of '57. Who knows when that got to the assembly line. For example, the drawings show the script on the valve covers was changed from low to high in January of '58 but yet NCRS judging is saying only low script valve covers were used in '58.

Do you know what was used on the shielding in '57?

Ted

[Ted S.]

Re: '58 Ignition Shielding Bolts

In looking in Noland's book it looks like the '57's used the wingnut bolts as shown in the diagram in the first post. Given the AIM drawing revision date of October on the bolts and the radio installation sheet I attached, it would seem at a minimum early '58s also used the wingnut bolts.

What am I missing? Anyone know when they changed in production to the chrome bolts from the wingnut bolts?

Thanks, Ted

[Ted S.]

Re: '58 Ignition Shielding Bolts

Given the research so far it would appear that early '58's used the wingnut bolts rather than the hex bolts for the top ignition shielding as stated in the TM&JG. Both the AIM and the Radio Installation Document support this.

1- The AIM shows revisions on 10-2-57 and 1-23-58. On 10-2 GM changed the picture of the bolt. The revision is only indicated on the top bolt and not the other 2. On 1-23 GM changed the part number from the wingnut bolt part number to the new part number for the hex bolts. This revision is shown on the back two bolts with the top bolt carrying the new part number. All three are indicated to use the same part number.

2- The radio shielding installation drawing is shown to have been drawn or approved on 12-17-57 showing the wingnut bolts in all 3 places on the top shielding. This document came from a kit that was sold to install a radio in a corvette that didn't have one. It included all the parts such as the radio, the radio support bracket, speaker, all the shielding, the ground straps, capacitors, bolts, etc. In the kit I had it only included the wingnut bolts. Most of the shielding was wrapped in 1958 newspapers.

So it appears that '58s didn't change to the hex bolts until sometime after January of '58. I am working up through the judging chain with the supporting documents and will let you know the outcome. Hopefully this of interest to some of the '58 owners.

If someone out there has a known original '58 I would love to hear from them.