1966 1967 Lower Valence, Radiator Core Support, Valence "Cut-out" Details

[Richard M.]

In another post I brought up what I thought were differences in the 1967 front lower valence between small block and big block cars. As it turns out I was mistaken in my interpretation of some of the different features between the SB and BB cars. Gene Mano helped me understand the differences and corrected my misinterpretation of what I posted, Here and more info I posted after Gene's reply Here.

I spent much time yesterday, researching, looking at several original cars, making phone calls and emails, and getting photos from others to help me. Here are the findings. If you have more photos and details to add to this please feel free to jump in.

Here is another thread with more info and pictures that a friend helped me research.
https://www.forums.ncrs.org/showthre...190#post568190

For 1963 through 1967, the lower portion of the radiator core support is attached to the lower valence using 2 L-Brackets. The brackets attach at the bottom to the headlight valence support rods with a bolt through the support, one on each side. Every AIM page from 1963 to 1967 shows the same detail. However, the 1966 and 1967 AIMs are wrong in their view of where the screw passes through the valence.

Here are the AIM pages in question. The 1963 to 1965 page detail is the same, except for revision data.

1967/1966 AIM, but visual detail of screw placement is wrong. Only 1963 to 1965 used the rearward valence hole.





In 1963 to 1965, the core support L-bracket attached to a hole in the lower valence, close to the rear edge of the valence as shown in the AIM page above. There was only one hole on each side. A Phillips screw and lock and flat washer, painted body color, held it to the brackets. The core support and screws/washers were installed before paint so body color was applied to these fasteners.

Here is a photo of a pre-1966 SB core support. Note the position of the lower side holes that attach it to the inner skirt.


Here is a photo of a 1966 SB core support courtesy of Rich Mauser. 1967 is similar. Note the added lower side bracket. This moves the bottom of the support more forward in the valence. A new hole was made in the valence, apx 2" forward of the original rearward holes to accommodate the core support change. The 1966/1967 AIM page does NOT depict the forward added hole and can be confusing.


Here are photos of a SB 1966 lower valence area. The core is removed but the L-brackets are still attached to the valence. Note the 2nd hole in the valence for the new core support placement. The rear hole was left open and not used.




Driver Side


Passenger side


The rods and brackets for another SB 1966, same for BB, and front view with the support rods and hardware attached. A 5/16" bolt passes through the core support and threads into the support rod (weld nuts) to hold the brackets to the core support.






1966 and 1967 Big Block cars used the same forward valence holes as shown in the pictures shown in the earlier thread. Here are some photos of a 1967 BB core support for reference. Note the additional side brackets which kick the bottom of the support forward just like the SB cars did. (note photo is showing support upside down hanging after I painted it)




========
Now, one more issue that I posted, as taught to me some time ago, but I was wrong about also. The lower valence Passenger side "cutout", just above the lower front bumper crossmember brace.

This cutout.....on a original valence BB car


And this cutout, on a original valence SB car....


Driver side references, SB & BB, no "cut outs".

SB


BB


I was taught it to be a BB identifier due to the bigger radiator. My recent examples show, as Gene also described, that it was also cut out on SB cars. There is no clearance issue to the lower bumper brace or other hardware when the body is mounted on the frame, either SB or BB.

I do not understand why did this had to be cut out. Was there a clearance issue. Factory Body dollies or fixtures? Ideas?

Rich

[Gary B.]

Re: 1966 1967 Lower Valence, Radiator Core Support, Valence "Cut-out" Details

Richard,

I can't answer any of your questions, but I just want to say that I think you've done some nice research.

Gary

[Gene M.]

Re: 1966 1967 Lower Valence, Radiator Core Support, Valence "Cut-out" Details

Richard,

I can't answer any of your questions, but I just want to say that I think you've done some nice research.

Gary

I'll second Gary's post Rich did a real nice job showing the configurations.

[Leif A.]

Re: 1966 1967 Lower Valence, Radiator Core Support, Valence "Cut-out" Details

Rich,
As is typical with all your posts...well researched and heavily documented with clear pictorial support. Thank you.

[Rocco S.]

Re: 1966 1967 Lower Valence, Radiator Core Support, Valence "Cut-out" Details

All,

Interesting post. It got me curious so I just looked at my recently acquired 67, L-79 small block coupe. It is an unrestored car with the original radiator. The lower valance is cut as described on the right side only. It appears that it was cut for clearance for the bottom tank of the radiator.

[Richard M.]

Re: 1966 1967 Lower Valence, Radiator Core Support, Valence "Cut-out" Details

Thanks gents......and Rocco, thanks for adding your findings. All data helps.

More research.

The valence cutouts are on both AO Smith AND St Louis built SB & BB cars from my research photos. I have some other AO Smith SB car photos with the same cutout. I don't know if AO Smith did the cutout before shipment to St Louis. It's possible all were cut at St Louis, regardless of the body source.

Here is a BB valence.....

Cutout on Pass side.


No cutout on Driver Side


The radiator lower neck is close to the valence on this BB but doesn't seem to be that close to warrant the cutout. Maybe it was just a precaution that Engineering decided due to the core support forward placement. I thought it may have been the St Louis Body dollies, but hard to see the valence and dolly bracket hardware....


Courtesy photos above from John Hinckley references from

http://www.michiganncrs.org/resources/StLBodyPaintShop.ppt

other references from John:

http://www.michiganncrs.org/Downloads/downloads.html

Maybe we will never know why the cutout was made. There is absolutely NO reference in the AIMs for this modification to the valence.

Rich

[Rocco S.]

Re: 1966 1967 Lower Valence, Radiator Core Support, Valence "Cut-out" Details

Rich,

I should have mentioned that my 67 is a St. Louis body# S4670, assembled late March. See the photo of the cutout and lower radiator tank.

[Richard M.]

Re: 1966 1967 Lower Valence, Radiator Core Support, Valence "Cut-out" Details

All,

Interesting post. It got me curious so I just looked at my recently acquired 67, L-79 small block coupe. It is an unrestored car with the original radiator. The lower valance is cut as described on the right side only. It appears that it was cut for clearance for the bottom tank of the radiator.

Rocco, Great photo, thank you. I now think the cutout was a production line precaution, as on your car it's certainly close to the radiator lower hose integral extension.

I don't have a better photo of a BB car at that same angle showing the proximity of the cutout to the radiator. Anyone have one to post?

I went through some other photos I have of a 1966 SB car. Although it has a hand laid one piece nose, I can see the lower tank is quite close to the valence. This valence was uncut as it was a replacement nose and shows it's close, but still clears.

Also note the "rearward" L-bracket early valence hole is not there as this was not a GM piece. In looking at these photos again, I am the one who drilled the valence holes for the L-bracket Phillips screw as the brackets were missing on this car. This should have been a indicator to me then about the forward hole placement. I guess I missed seeing the forest through the trees in front of me.










Rich

[Gene M.]

Re: 1966 1967 Lower Valence, Radiator Core Support, Valence "Cut-out" Details

It's my guess the right side front valance notch was done prior to painting. I say that since I've not seen any with raw fiberglass cut edges. Saying that I've implied the AO Smith arrived with notches and not done at St Louis. But I have no facts to back it up other than what the cars say from observations.

[Tony S.]

Re: 1966 1967 Lower Valence, Radiator Core Support, Valence "Cut-out" Details

Didn't see if your car is a '67 BB car or not. Is your car an A. O. Smith car?

[Richard M.]

Re: 1966 1967 Lower Valence, Radiator Core Support, Valence "Cut-out" Details

Didn't see if your car is a '67 BB car or not. Is your car an A. O. Smith car?

Tony, All of my photos are of various other SB cars(not mine) from both AO Smith and St Louis. Both had the valence cutouts.

The Black car photos with the valence cutout is a Big Block car, certainly a St Louis built body.

Rich

[Brian K.]

Re: 1966 1967 Lower Valence, Radiator Core Support, Valence "Cut-out" Details

My 1966 AO Smith March 4th build L79 convertible has the cut out on the RH side and double holes drilled in the lower valance.

[Richard M.]

Re: 1966 1967 Lower Valence, Radiator Core Support, Valence "Cut-out" Details

My 1966 AO Smith March 4th build L79 convertible has the cut out on the RH side and double holes drilled in the lower valance.

Brian, If you get a chance, please post a photo at a angle(like Rocco's above), which shows how close the radiator bottom tank is to the valence. It would be another data point to help my research.

Thanks,
Rich

[Richard M.]

Re: 1966 1967 Lower Valence, Radiator Core Support, Valence "Cut-out" Details

It's my guess the right side front valance notch was done prior to painting. I say that since I've not seen any with raw fiberglass cut edges. Saying that I've implied the AO Smith arrived with notches and not done at St Louis. But I have no facts to back it up other than what the cars say from observations.

Gene,

It seems feasible that it was done before paint but as you say, since there is no engineering documentation it's a mystery. Since the paint process shot from the front, and lightly in that area, IMO the cuts probably wouldn't have paint on them anyway. If paint is on the cuts, it might tell me it's a repainted area. If no cutout, it might tell me the valence isn't original.

Economically, the valence cutouts, as well as the 2 extra L-bracket valence holes, were probably done right after the raw valences came out of the molds, at either facility, AO Smith or St Louis. I have no facts either but it may be what happened. Only a St Louis historian may know for sure.

-------
More thoughts on WHY the cuts were there on ALL SB & BB cars....
The sample photos, both mine and others who are posting their photos, clearly show the clearance variation of the valence to the radiator. I'm seeing some close, some distant, and even some nearly touching. Then I thought of why, and now I think it's relatively simple why the cuts were made.

During body build, the variation of the attachment of the top surround to the inner skirts and variation of the attachment of the radiator core support to the inner skirts might have played a role in this clearance. The core support lower horizontal distance to the valence varied during body build. The L-bracket could either push or pull the valence when assembled based on these variations as the bracket has a fixed dimension. I've seen this on restorations I've done. Bonding adhesive thickness, inner skirt core support hole diameter variation, core attachment to inner skirt variation, and panel dimensional differences probably resulted in different clearances at the bottom near the installed radiators, both on BB or SB builds. So they probably did the cutouts as insurance for assemblies that might be too close.

It's all speculation, WAG, or whatever, but that's my opinion of it all. The fun part is.... I learned something new with this research.

Rich

[Gene M.]

Re: 1966 1967 Lower Valence, Radiator Core Support, Valence "Cut-out" Details

Rich,
Maybe when John Hinckley get better perhaps he can shine some light on the valance cut out. I can see with all the tolerance build up that the close proximity of parts can have wide extremes. I like your observations it could be as simple as assembly clearance.