Can anyone tell me if this hole belongs on the floorboards?
It is right next to the mounts for the bucket seat tracks.
The hole appears to be factory and does not look like it was drilled.
There are one on each side, drivers floor and passenger floor.
It does not appear to be a drain.

I'm not real sure with out a bigger area picture, but that wouldn't be for a drive shaft loop, somebody was dragracing and put in.

Rob

Definately does not belong there. As Rob suggested maybe for a loop, or possibly an attempt to copy the holes under the rear seat for drainage, although the spot you have a picture of is not a typical rust spot for the floorpan.

Both drivers side and passenger side have precisely the same holes in the same position.
They have a raised area to them, so it does not appear to be a drilled out hole.
These holes are right in front of the rear mounting nuts for the seat tracks for the front seats. So I do not think these have anything to do with a driveshaft or racing.
Remember, this is a convertible, so the floor may have a different configuration than a hardtop.

For example, on the transmission tunnel, the hole cut out for the staple shifter cable, someone had double drilled the holes side by side. It appears to be factory, but there is no way of knowing, so we cut a round piece of metal and welded it in to fill part of the hole. I do not want any air leaking in from underneath the car. The picture shows both holes before we welded the one on the right side.

Fred, The convertible floor pan is not any different than a hardtop, the two interchange exactly. I own a convertible as well and I answered the question based upon your sig, believing the 68 convertible to be the car you might be referencing. The holes don't belong there via the factory. Is the car originally a bucket seat car? If not that is about the only other thing I can come up with. Someone likely drilled a hole to bolt the seats to the floor, or possibly had something other than chevelle seats installed in the car in the past which wouldn't fit factory track alignment. It's 38 years old, people tend to do funny things to install items in cars no longer in their prime.

Fred, The convertible floor pan is not any different than a hardtop, the two interchange exactly. I own a convertible as well and I answered the question based upon your sig, believing the 68 convertible to be the car you might be referencing. The holes don't belong there via the factory. Is the car originally a bucket seat car? If not that is about the only other thing I can come up with. Someone likely drilled a hole to bolt the seats to the floor, or possibly had something other than chevelle seats installed in the car in the past which wouldn't fit factory track alignment. It's 38 years old, people tend to do funny things to install items in cars no longer in their prime.

I absolutely agree. Anything could have been done since the car was built.
But looking at these holes, the exact position from one to another and the way the lip curls up, it looks factory to me. It is a bucket seat and center console car. I guess I will fill them in or put a body plug in them.

The original, unmolested floors on my bench seat, non-console '68 coupe do not have the holes. Sometimes people who worked on these cars actually measured and drilled holes accurately, all of them weren't boneheads.

BillL

Those holes are not factory. As mentioned before, someone probably installed nonfactory seats and drilled out those holes. I am in the process of restoring my 70 chevelle, and I also have similar holes drilled that are NOT factory. You can see those pics in my showroom, under scottie.
Plus if they were factory, they would have a cage nut in the hole where the bolts thread into. Just a hole in the sheetmetal with no reinforcement or backing plate would rip out of the sheetmetal under stress.