Where do the four pads shown on the left in the attached picture go on the rear vent plenum?

 

In your pic of an Astro Ventilation rear deck seal kit, I don’t believe the four pieces at the far left are used on the car, as they are merely the cutouts for the two gaskets immediately to the right of them. The three holes in each of the four seals to the right of the two gaskets accommodate the rubber rivets.

My understanding is that only corvettes without factory A/C (1968-1976) were assembled with operable Astro Ventilation. The system was not needed on A/C cars, but the grilles, plenums and often the script call outs on the two side windows were present on all cars during those model years.

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1979 L82 M21 FE7
Classic White / Doeskin

 

Thanks for confirming the assumption to which I arrived. It was obvious where all the other pads went but there was just no place for the four cutouts. Mine had a functioning Astro-ventilation system - at least at one time. When I disassembled the car, the steel vacuum tubing that runs under the carpet on the console and behind the passenger seat was in pieces. Fortunately the diaphragm in the actuator is still in good shape because, except for the pads, parts are non existent. Everything is back together now and seems to be working but I wonder if it was worth the effort.

Thanks again.

 

You're welcome. We're here for each other.

I believe the metal tubing running along the console was copper. My understanding is, if the system is working properly, whenever you move your temp dial to "C" then the system will flow outside air through the cabin and it exits the rear grilles. If you move your temp dial to "H" the air is shut off.

Most of the owners I've read and spoken to seem quite underwhelmed with the effectiveness of the Astro system, but it did have a cool name. I've read that Chevrolet deleted Astro Ventilation about '74-'75 due to the ever increasing percentage of cars ordered with A/C; Cars that Chevrolet deemed to have no need for such a system.

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1979 L82 M21 FE7
Classic White / Doeskin

 

That's probably true because I imagine very few cars have been built since then without air. When I bought this one I specifically didn't want power steering or air which would rob power from the LT1 engine. I originally wanted a '70 but found a Corvette guy who had ordered mine after the end of the '70 production and didn't know they were going to detune the '71's He immediately put a cam, "Tarantula" aluminum intake, a Holly double pumper and headers on the engine but left the 9.0 to 1 heads. The car could blow the doors off a any '70 LT1 but burned the cheapest unleaded regular with never a ping. Best of both worlds. He also had a friend who worked at Jon Kosmoski's House of Kulor (paint now owned by Sherwin Williams) who painted it candy tangerine over mother of pearl white with white stripes on the sides around the louvers and hood where the LT1 stripes were. He added maroon pin striping on both sides of all contours and maroon shading out from the striping.. It has been a fun car and I can't wait to drive it again. Finding someone to replicate the paint job will be a challenge.

Anyway, I found the metal tubing replacement from Doc Rebuild and sorry to bend your ear.

Thanks and have a wonderful week.

Jm