1963 Top ignition shielding design changes

[Richard G.]

My upper Corvette Ignition Shielding was determined a service replacement during judging.
I am looking to find an original.
Basic knowledge is the 1963 top shield should have three rivets on the top and two grounding clips. Or one riveted on and the separate part that fits the cut out on the back.

Basically, two different designs. And the second design has two variations (T grounding tab and straight tab)

Early design changes.

1. 1. Without the FI & CARB cut outs
   2. With the FI & CARB cut outs
      1. Later Shields with the FI & CARB cut outs

Judging manual refers to the FI & CARB holes starting about vin 10.000. My car is a 1055xx Vin and should have the stamped FI & CARB cut outs on the back. Clear enough.

The grounding tab(s)
Till Vin 1100- the tab was straight. After approximately Vin 11000 the "T" style ground tab" was used through the rest of 1963 and 64. Early style (straight grounding clips are acceptable to Vin 12000.

What is unclear is the approximately. How much earlier than the 11000 Vin would the "T" style top shielding be acceptable?






Thanks
Rick

[Loren L.]

Re: 1963 Top ignition shielding design changes

Your 55XX should NOT have the FI - CARB slots in the back. These are basically associated with an increased demand for grounding caused by the AM-FM radio option, as well as the "T" front ground. Cars around 12,000 should be evaluated on the basis of what radio is installed, tempered by the fact that some very late AM radios undoubtedly received the later shielding.

[Richard G.]

Re: 1963 Top ignition shielding design changes

Loren;
Thanks for the information, much appreciated.
However your answer doesn't appear to match my understanding of the information in the JM. Don't get me wrong, I believe you. I just want to understand this and do it only one time. Of course, my car has the AM only radio.
I’ll quote the JM below;
"Distributor shields are a polished stainless steel stamping with ground clip on both the front and rear with the exception of early 1963 distributor shields (up to approximately VIN 10,000) That have no slots for the rear grounding clips."

My VIN 1055xx seems to fall between the early shields ending at APPROXIMATELY 10,000 and the AM-FM radio debut at VIN 12,000.
So my car would require the early (no FI - CARB slots in the back) and the "T" style grounding. Which is the only grounding tab this early style shield came with. The way I understand it now the JM should indicate the early style shield would end at APPROXIMATELY 12,000 when the AM-FM appeared not the 10,000 it currently quotes.
The 63’s are a special car and understanding the running changes is a challenge.
Thanks
Rick

[Mike L.]

Re: 1963 Top ignition shielding design changes

We should not believe everything in the 63-64 Judging Manual, this manual needs to be revised. My friend owns # S109_ _ , 63 Corvette and it was proven it came from the St. Louis factory with a AM/ FM radio. He has paper work from GM that the radio was available. It's very hard to change some people's mind.

[Richard G.]

Re: 1963 Top ignition shielding design changes

Thanks Mike and Loren for your input.
A little disheartening to do the research, using the latest manual, and find out my car is an "betweener" and the manual is incorrect. Not for all cars but for about the 2,000 of them or 10%.
I was happy I got my car judged. The Judges found many items I didn't know about and the SR ignition shield was just one of them.
Rick

[Chris D.]

Re: 1963 Top ignition shielding design changes

Vin 1104X, AM wonderbar, no slots, straight grounding tab. A wide overlap for this type of transition should be expected.
Chris

[Loren L.]

Re: 1963 Top ignition shielding design changes

Richard, you can't have it both ways; your first "After approximately VIN 11000, the 'T' was used"; your second "...the 'T' style grounding, which is the only grounding tab this early style shield came with...".
The straight (non-T" grounding strap is the strap for the AM radios.
Mike, I do not doubt that there is February paper work on AM-FM radios. The first shipment of AM-FM radios to St Louis was on Feb 27, 1963 IIRC. They were done on a "use them up" basis and were not installed until circa 12,000.
Like Chris, my car is 10706 and it came in 1972 to me with a straight grounding tab and no slots. $1100 and I drove it home.

[Richard G.]

Re: 1963 Top ignition shielding design changes

Yes, the "T" style is the later design. My bad.
This would have been so much clearer if the JM just listed the early shield for AM only radios and the later for the AM-Fm.

To address the grounding tabs (straight and "T" styles)
I have observed the late style 63 top shield with the FI & CARB holes with both style grounding tabs.
Seems the tabs may have not changed at the same time GM added the cut-outs to the back?

[John D.]

Re: 1963 Top ignition shielding design changes

Richard, Wonderful presentation you did on the two ignition shields aka distributor shields. My 63 FI car is in the 9900 range. Came with the early shield as of course has the AM radio. When I first had the car judged there was some debate on the shield on my car.
I solved the situation easily by showing the car with both style shields. Both wrapped in saran wrap. I did it for a fun thing.
It's been quite a while since the car was judged. By now the early shield is recognized to be correct for my 9900 car.
I don't discuss judging manuals on this site or any site.
As stated above your car with the AM radio should have the early shield. Thanks for the nice pics and info. John

[Ronald L.]

Re: 1963 Top ignition shielding design changes

Question on the rivet size on the top...

The later version has very small rivets?

What are the originals? (I don't see 3/8" in those pictures...)

[Loren L.]

Re: 1963 Top ignition shielding design changes

Ron, I attempted to micrometer the rivets in my EARLY top shield - by the way, the rivets in the top shield appear to be the same in the air cleaner strap - they appear to be .030 WITH A WARNING: I may be kidding myself when I feel that the blades of the mic are NOT slipping up the rounded dome of the rivet. I'd be far more comfortable measuring a rivet that was NOT installed. File under "FWIW".

[Ronald L.]

Re: 1963 Top ignition shielding design changes

Loren, Maybe thats what was happening, even very carefully, I was getting .23", thank for trying.