It's pretty safe to say that most muscle car owners prefer bucket seats and a console to a big, flat bench. Maybe its because the super cars of the day were mostly optioned out with buckets, or just the simple fact that we each want our own seat. A truer statement would be buckets tend to hold you in place better when the car goes into a turn. As an ex-upholstery guy, this author has seen his fair share of "questionable engineering" hiding under seats. I have seen everything from holes punched in the floor with a screwdriver and some 1/4-inch hardware, stacks of washers way too tall, and all kinds of sketchiness in between. The most offending thing was seeing holes in the floorboard with no backing plates or added strength to the mounting area. Who knows what would happen to that seat (and occupant) in the event of a crash!
Thanks to Auto Metal Direct, you no longer have to come up with your own idea of engineering when it comes to converting to bucket seats. The company has just completed production on a set of factory-style floor mounts that you can weld to the floor, providing the proper mounting points for a bucket seat. Not only will the seat mount to a strong piece of floor, it will be at the correct height to allow the seat to sit level. The stamped brackets are punched out of 18-gauge steel and look similar to the '68-'72 versions, but will work on the '66-'67 models as well. The four-piece set features correct holes, studs, and shapes like original, but unlike originals, these parts are EDP coated, for rust resistance inside and out. The mounting bracket set is a licensed reproduction under the official GM Restoration Parts licensing program and retails for $49.95.
1 Here's the Bucket Seat Mounting Bracket set from Auto Metal Direct (AMD), part number 407-3466-S. It's a four-piece, 18-gauge stamped steel bracket set modeled after the '68-'72 brackets, but it will still work for the '66-'67 floors as well. The two larger pieces will go inboard next to the tunnel and the two smaller brackets are for the outside front mounting point. The outside rear didn't get a stud from the factory so this is all you'll need, except for some fine thread nuts to go on the studs. One nice thing is these are EPD coated so you won't need to paint them or anything before the install.
2 Here are the inner bucket seat brackets on the floor of our '66 Chevelle. As you can see, the studs are missing and someone has drilled and tapped where the stud used to be. This is not the best way to secure a seat, as the metal is not thick enough to provide enough threads to hold the seat in the event of a major impact in a wreck. The bolts could simply tear out of the floor. Another thing you might notice is these factory brackets are much wider than the ones we are installing. While the new ones are thinner, they will still be ample enough for our seats, since the factory redesigned them for the '68 and up models.
3 Same sort of scenario over on the front bracket as well. Bracket in place, stud missing and a hole drilled. Also, these outer ones look like there were cut off and replaced at some point in this car's life. All our issues will be fixed by the end of the day—well, the seat bracket issues anyway.
4 This will give you a good idea of the differences in the brackets. Again, even though they are shaped differently, the new ones will work just fine. This also showed us that the studs in the bracket are spaced the same and will fall in the proper position.
5 Before we cut the old ones off, we measured the location of the studs and made a bunch of marks so we can get the new unit back in the same position. We will give you all the measurements at the end the story.
6 We had to chip off some sort of black tar-like substance that was covering the welds.
7 Then we sliced through the welds with a grinder. We thought the bracket would pop right off once we got the perimeter welds cut, but boy were we wrong.
8 Apparently GM decided to spot-weld them as well, so we had to find all of them before we could continue. We used an air grinder to locate the spot welds. We kept the grinder flat so it would quickly clean off all the high areas and leave us a telltale dot in the low areas.
9 With an Eastwood Skip-Proof Spot Weld Cutter, we cut out the offending spot-welds.
10 After some more cutting, grinding and prying (and a few choice words), the factory panel finally popped free. We found 32 cents, some sort of old battery, and a gum wrapper hiding underneath. Score!
11 After getting all the factory brackets cut from the floor, we used an electric grinder to remove the rest of the remnants.
12 Following our measurements we tacked the outer brackets in place ...
13 ... followed by the inners.
14 Then, just to make sure everything was copasetic, we dropped in a bucket seat and sat down. It all looked and felt right, letting us know our placement was good to go.
15 Then we finished welding the brackets in place. There is another way to locate the seat that is a lot less precise than measuring it all. Mount the brackets to the seat tracks and then drop it all in the car. Install the one bolt in the inner hole of the outside rear track, line up the seat to your liking, and tack or mark the brackets and go from there. We prefer to use measurements, but it's not nearly as quick.
16 For you more precise people, here are our measurements for a '66 Chevelle. Note measurement B starts at where the rocker meets the floor. Also, there will be two holes at the outer rear location. For a bucket seat application you will not use the outer hole (see arrow).
A is 13 inches
B is 6-3/4 inches
C is 15-1/8 inches
D is 14 inches