Floor Pan Replacement on Convertible

Q: Floor Pan Replacement on Convertible

I got me floor pans for the conv.. Here we go … Get ready for the questions. Going to pull the seats and carpet out this weekend to take a peek.

1. Does that Scott Jason camaro restoration book have any good info on this subject?

2. I have a Fisher Body book for 1968 I find it screchty on the Fbody data covers all body styles is there a manual in print just on the F body,

3. Anyone ever done this with out taking the subframe out of the car?

4. Seat perches have to come out?

5. How about that cross member on the tunnel for convertibles. I ain’t seen a car yet with that installed. Does it bolt to the floor pans? No threaded wholes in the new pans.

6. Body bushings bolt to the floor pans … right. No holes. Logic tells me that fabricaing and welding the pan in takes some BFH and that you measure and align after all is welded in place. How? Measurements?

The pans are one piece left and right from Classic Idustries. I beleive the sticker says the company that made them are American Design. Anyone had any expreince with these? Should I stop right now and send them back? Fit like _hit. Knowledge is everything. I am not a body man. I plan on doing everything but cutting them out and putting them in. I will find a body guy to do this. I need to arm my self so I can ask the right questions and tell if the job is going to be done right. This is not a concours restoration I’m looking to get it done quickly and cheaply.

A: Just a couple of things that may help…

Floor pans can be replaces without removing the sub-frame. I’ve done it on both a convertible and coupe without any problems. I also highly recommend additional bracing for the convertible. Also, take measurements of the door gap BEFORE you rip out anything. Check these measurements BEFORE you weld anything.

Coupes are pretty easy and straight forward. Refer to the FAQ for a previous write-up.

Convertibles are a little more difficult because of the belly brace but once you remove the seat pedestal and the old pan, it will help you align the new pan. Remember the additional brace that is just in front of the rear seat hooks.

On both installations, I used the “turned up” style of replacement. This makes welding easy as it’s all done from the top. I used tube style body caulk to fill the cap at the bottom. Once painted it looks OK. While my car was up on the rack getting a new exhaust, I received a lot of good comments on the pans from a guy who runs a local restoration shop.

There are pans available that turn down to mimic to old pans. I found some from a vendor at a swap meet. I don’t have his card but I think a company called C.A.R.S. (www.carsinc.com) carries them. These will allow you to make the pinch-weld below the rocker panel like the factory.

I pre-drilled all my welding hole and the rear frame rail mounting hole before I welded the pan. First I trim and install the pan with sheet metal screws until I’m satisfied with the fit. I temporally re-mount the seat pedestal also using sheet-metal screws. Once satisfied, I use a pencil to trace around the bottom brace and through the seat pedestal. This gives you an idea where to drill the spot-weld holes and where to drill the hole for the body to frame-rail bolt.

After I’ve drilled all my holes, I remount the pan, seat pedestal, and frame-rail bushing and bolt, check my measurements and weld. If your door opening seems to have sagged a bit, try to position some jack stands under the rocker panel closer to the front of the car to allow more weight on the rear. Do this slowly with a floor jack under the rear-end.

A: 4. Seat perches have to come out?

If I recall correctly,which I do,them there “perches” are spot welded in,and as such can be hacked out. Thats what I did,I never even considered going the route of removing the sub frame, though if you do,that would be a good time to get some new body bushings.

A: I have just finished putting floors in a 1968 Convertible. You can’t see all the areas that may be rusted from the inside. Get and Ice pick or something sharp to poke with.

3. since the subframe bolts to the seat perches I don’t see a way to get them out with out removing the subframe.
4. If you are going to replace the whole pan and I would suggest that, then yes they will have to come out. There is also a reinforcement plate at the rear of the floor that will have to come out too. Under this is one place I found a lot of rust that I couldn’t see before I removed it. There was also a lot under the seat perches. The Hooks for the rear seat will also pose a problem. I cut the old floor and new floor around them and left them attached. My floors were fine in that area.
5. The Convertible Plate bolts to the frame not the floor pan.
6. I cut the holes in the pans for the subframe after I had the seat perches welded in. I drilled and small hole from the inside through the mounting nuts fastened to the seat perches to mark the center of the holes and then used a cut off toll to make them large enough.

One other area that was a problem was that the new floor turns up or in on the out side of the floors and the originals turned down or out. I did different things with each side of mine and wasn’t happy with either so I will leave that up to you.

A: 1. Nope, Jason Scott says nothing, however the list archives contain very good explanations of what to do.

4. Definitely remove seat perches and rear reinforement plate, these covered a lot of hidden rust on my car. These can generally be repaired and reused.

5. The conv. reinforement plate bolts to the belly-brace, not the floor. It is much easier if you can remove the floor and leave all underfloor bracing in place. This assumes that your floor is rusting from the inside out and the underfloor bracing is good.

I used the Classic pans and even though I haven’t welded yet, trial fit is fine. Seems that SFH will suffice.

Again read the archives for the old posts.

A: On the Passenger side I cut the old pan at the edge of the Rocker. This tended to leave a gap where the new floor meets the Rocker from the bottom. It has the potential to get and hold water. I plan to seal it with seam sealer. On the drivers side I cut the old floor about 1/2 to 3/4 of an inch from the rocker and set the new floor on it and welded it to it. This creates a better seam from the bottom but creates a possible problem in areas where it was hard or impossible to weld. The cross member and the support on the bottom Front of the floor.

Another thing I did was to do one floor pan at a time. This was a suggestion I read earlier on this list. This was because the floor is such a big part of the support for the car.

I have mine turned on its side to make it easier to work on.

A: I’ll answer what I can:

3. My subframe was out
4. Take out the seat perches
5. Convertible reinforcement plate bolts to the extra bracing that only the convertible has (under the floor boards)
6. I measured and then drilled the holes after installation. The subframe “nut” is loose and can move around a little. The hole has clearance so the bolt and nut can be move for alignment.

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