I am trying to validate an issue regarding a 1974 Corvette Coupe. In the rear, just ahead of the gas filler door are 2 rectangular grilles painted the body color. They screw on with phillips head screws.
Below that is a solid panel. I have seen vehicles with the panel below the grilles painted flat black, and have also seen vehicles with this area painted the body color.
Does anyone know what is "Factory Original" and "Correct"?
Flat Black Underneath or Body Color?
AB - with the differences you've noted, is there any correlation between AC and non-AC cars?
Good point!
The car I am trying to validate is a 74 with factory a/c
the panel below the rear deck vents is solid vs hollow like I have seen on some earlier years, so this vent is non-functional. Are there differences in this area for a/c and non a/c?
74 and earlier non-air cars had "Astro-Ventilation", a flow through ventilation system using vacuum operated exhaust vents under the rear deck grilles. When the kick panel vents were openned, the deck lid vents would open to vent air out from the interior. I don't believe air cars had the vent system and as such, used a solid panel under the deck lid grilles.
I took a quick look through the 74 assembly manual. Though it shows the installation of the grilles and vacuum vent assembly on non-air cars, it doesn't show anything referencing the instalation of the grilles on an air car or if the area was "blacked-out".
I bought a 74 air car in 79, it was a very low miles, white, original paint car. Looking at some pictures I have of the car here in my office, I can't tell if it was blacked-out under the grilles and I don't remember. I know the current owner of my old 74 and the car still has the original paint on it. If no one comes up with an answer for you by tonight, I'll try and call him and ask him to take a look at that area for me.
I would tend to believe that GM blacked-out this area, at least on light colored cars (white, silver, yellow, etc.), but maybe not on a black or dark blue car.
I'm not a C3 guy, but I recall a discussion on this issue several months ago over on the NCRS Board; the consensus was that the "well" was blacked-out after body color, but the flange around the opening (where the U-nuts for the grille screws are applied) remained body color.
...the consensus was that the "well" was blacked-out after body color, but the flange around the opening (where the U-nuts for the grille screws are applied) remained body color....
From the NCRS Judging Guide regarding the "Rear Deck Vent Grilles" on page 49 (second edition with updates): "A blackout operation left the flat mounting surface black, but no black on the sides of the grille recess."
I don't recall the flat mounting surface on my car being black (white body, convertible, air conditioning), but there are indications that mine may have been repainted - maybe by the dealer before delivery.
The judging guide goes on to explain the operation of the "Astro Ventiliation" and notes that AC cars have the block-off plate. You can still see down in the recess, so I would think that the black-out operation would be consistent between AC and non-AC cars. But I'm no expert in this matter.
Also, it goes on to say that on convertibles, there is no bottom to the air box. You can see the top of the gas tank, and see down to the ground.
__________________ Send Me your 1974 VIN number and info: PS, PB, PW, Tilt, AC, int/ext color, leather/vinyl, etc.
Corvette Store
74 Vette Rear Grilles - Black Underneath or Not?
