C3 Underdash Brace Rods?

[Patricia Brown]

Hello,

I have a gutted '72 body that I am trying to determine whether it is supposed to have underdash brace rods. I am looking at the A.I.M., page A9, where it shows 4 rods (2 rods on DS running from strg. col. support to hinge pillar gusset area; 1 rod center upper dash to strg. col. support; and 1 rod from center upper dash to PS hinge pillar gusset). I was told that these rods were only used on the convertibles, though the A.I.M. does not specify only 'verts. Is that true? Do these rods belong on my non-'vert car?

Thank you!
Patricia

[Jim T.]

Re: C3 Underdash Brace Rods?

I believe/think I have read somewhere that the rods were used on C3's when the body style was a convertible. The rod braces were not used on early 68 convertibles as my Feb built 68 convertible does not have the reinforcement.

[Jim T.]

Re: C3 Underdash Brace Rods?

My original owner 70 coupe does not have the reinforcement.

[Joe L.]

Re: C3 Underdash Brace Rods?

Patricia-----

The underdash reinforcing rods are for convertibles only; they were not used on coupes during the 68-75 period.

Actually, the AIM does specify that they are for convertibles only but it's not readily apparent. You will note that on the page which details the reinforcing rod installation, the block on the lower, right side of the page says "model 19467". 19467 is the model number for convertibles only. So, this page applies to convertibles only.

[Patricia Brown]

Re: C3 Underdash Brace Rods?

Thank you so much, everyone! I am relieved I don't have to scrounge these rods up!

On another note, would there be *any* advantage in adding these rods to a coupe car? Would there be any additional strength and safety, or would I be able to tell the stiffness difference?

Thanks!
Patricia

[Patricia Brown]

Re: C3 Underdash Brace Rods?

Joe-

Does 19000 refer to a coupe, then? And occasionally there is a 19437-what would that be for (hardtop?)

Patricia

[Patricia Brown]

Re: C3 Underdash Brace Rods?

OK-sorry for 3 messages in a row....but, on page A1 of the AIM I just noticed it shows an "underdash brace rod" in the drawing, and the model specified is 19000 (not a vert)....?

Patricia

[Terry M.]

Re: C3 Underdash Brace Rods?

The way it us supposed to work is:

19000 = ALL Corvettes for that model year

19437 = coupes only for that model year

19467 = convertibles only for that model year

[Chuck S.]

Re: C3 Underdash Brace Rods?

ALL Corvette AIM pages will show 19000 UNLESS there is a variation between the models.

For example, on the page that shows the installation of the convertible top, the bottom of the page will show 19467 because convertible tops are ONLY applicable to the convertible model. Conversely, the bottom of the AIM page that shows how to adjust the T-tops will show 19437 because convertibles don't have T-tops. The vast majority of AIM pages will show 19000 because the illustrated features are shared by BOTH the convertible and the coupe models.

A recent thread discussed rear ventilation vent doors. The correct conclusion for most readers was that air conditioned cars have solid plates blocking off the rear ventilation openings, while non-air cars have vent doors that open to provide air flow through the cabin. Some thought the difference was in the body model, which in incorrect in principle. There is, however, a difference in the way the vent doors are designed for non-air convertibles vs. non-air coupes, and this difference is illustrated by different AIM pages labeled as described above (70 AIM, UPC 1, page F20 and F21).

[Chuck S.]

More...

"There is, however, a difference in the way the vent doors are designed for non-air convertibles vs. non-air coupes, and this difference is illustrated by different AIM pages labeled as described above (70 AIM, UPC 1, page F20 and F21)."

Actually, a difference should be illustrated, but it is not due to an error in the drawing (UPC 1, page F20)...well, the coupe drawing DOES show different part numbers. It appears a lazy draftsman used the convertible vent door drawing for the coupe vent door, so the page F20 illustration generates confusion unless you know better.

The real difference between the vent doors in non-air C3 bodies is shown almost incidentally in UPC 1, page M4, Vacuum Control Hose Routing...convertible vent door actuators are on the passenger side; coupe vent door actuators are on the driver side. Uh, by the way, both hose routings are shown on one page...uh, labeled 19000.

[Patricia Brown]

Re: More...

OK, now I'm confused. Page A-1 of the '72 AIM shows one under dash brace rod, is labeled "underdash brace rods", and yet the page lists 19000, which indicates it applies to ALL models. SO, in that case it would appear my car needs at least this one rod which is illustrated...???

Patricia

[Terry M.]

[Terry M.]

Re: More...

My guess would be that is another AIM mistake. To the best of my knowledge no coupes of any year got the underdash brace rods, but you may want to hear from some folks who spend more time in Corvette interiors than me.

[Chuck R.]

Re: I too broke a sweat when I looked at that page

My first thought was "Great more M.I.A. parts"

Nice to know something on this ole shark of mine was "correct"

Regards,

Chuck #32205

[Chuck S.]

Re: More...yet

Sorry, Terry, I wasn't intending to upstage you.

You know me well enough to know I have a pedantic mind-set; when I suspect the reader may still not get it with an economy of words, I tend to overwhelm them with details...often so much it is confusing rather than enlightening. LOL

There are probably some school meisters in my family tree.