Floor Pan Drain Holes -- 1978

[Greg A.]

I'm looking for clarification on the presence or absence of plugs in the drain holes of the footwells in my '78. Currently, the holes are open -- no plugs. I have had others tell me there should be plugs installed, similar to the ones in the left and right storage compartments (several inches long with holes 4 holes in a cross pattern.)

If they were there originally, it doesn't surprise me that they are gone as they could easily be knocked out. The J&TM doesn't cover this area. Appreciate any help from those in the know.

Greg.

[Joe L.]

Re: Floor Pan Drain Holes -- 1978

Greg-----

There were definitely plugs in the floorboard holes. However, I don't believe that they were of the type used for the rear compartment drains. The rear compartment drains were GM #3948148 and I don't think that these plugs were used for the floor drain plugs.

In any event, I believe that Dr. Rebuild offers correct replacement floor drain plug kits for just about every model year Corvette

[Greg A.]

Re: Floor Pan Drain Holes -- 1978

Thanks for the quick response, Joe. I'll try to run down the correct plugs. I obviously drive in the rain from time-to-time in the NW, but have never had much of a moisture problem here...maybe you only get wet if you drive slow?

Thanks again.

Greg.

[Dale Pearman]

Re: Floor Pan Drain Holes -- 1978

There is no such thing as a floor pan drain hole or plug! These were access holes for body handling and in some models body attachment. They were definately pluged with a rubber plug.

Varooom!

P.S. Tell Jeff, (Dr. Rebuild) Dale Pearman said, "Hi".


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[Joe L.]

Re: Floor Pan Drain Holes -- 1978

Dale------

I'm afraid that GM doesn't agree with you. They refer to the GM #3948148 plug that I previously mentioned as "PLUG, underbody storage compartment drain". This plug is designed to allow fluids or gasses to flow out, but not allow fluids to flow in (except if the car is submerged).

The other plug, GM #4805844 for the floorboard area, is described as "PLUG, drain holes in underbody panel".

But, of course, what does GM know?

[Dale Pearman]

Re: Floor Pan Drain Holes -- 1978

GM dosen't know SQUAT! That's a well known fact. Don't forget, I'm a C1 man. I don't know squat starting August 2, 1962. Prior to that I do know that holes in the floor pan (under the carpet by the way) were plugged and were there for positioning of the fiberglass body on the fixtures at St. Louis during assembly. Condidering the integrity of the top systems during C1 production, a 10 inch sewer drain should have been installed somewhere in the floor.

Varoooooooom!


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[Dale Pearman]

Re: Floor Pan Drain Holes -- 1978

P.S. Then we'd be driving DYNA-SEWERS.

Varooooooooooooooooooooooooooooooooooooooooooooooo oooooooooom!


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[Joe L.]

Re: Floor Pan Drain Holes -- 1978

Dale----

I think you're right. With as little as GM knows, it's amazing that they ever got these cars designed, built, and out the door!

[Greg A.]

Re: '78 Floor Pan Drain Plugs Found & Installed

Joe and Dale,

I appreciate the comments. I stopped by my local shop (Pacific Corvette) on the way home tonight. They were parting out an '82 CE. It actually had 4 drain plugs in the passenger compartment (1 in each foot well, 1 under each seat.) I was able to get 2 good used ones for $6. They looked exactly like the drain plugs in the storage compartments.

When I got home, I carefully looked through my AIM and finally found the sheet for the underbody drains and plugs (A01 - A12, Sheet 13.) All four drain plugs for the '78 (1 in each foot well, 1 in each side storage compartment)are listed with the same part number 3948148 ("PLUG - DRAIN."). So, they all appear to be the same.

Plugs now installed, feet hopefully to remain dry!

Thanks again.

Greg.

[Joe L.]

Re: '78 Floor Pan Drain Plugs Found & Installed

Greg-----

Yes, I checked again now that I have my references available. Apparently, starting in 1977 GM went to using the 3948148 drain plug for all positions. Earlier cars used the 3948148 for the rear compartment only and used "solid" plugs for the floorboard holes.