I'd really appreciate advice on replacing the floors and support braces on my 69 Chevelle convertible. I've read many, many good posts on this subject over the past several months, but some questions still remain. (Facts: I have enough rust-through to warrant replacing all 6 sections of the floor pans, even though only the left front is totally hopeless. All three support braces have significant rust, and I'm assuming I should do the job well by replacing them now too. Tunnel is in very good shape; transmission and engine are off the car. Goal is a fun daily driver; I'm a pragmatic enthusiast, not a concours restorer. I'm also budget minded.)

1. A strong theme that everyone recommends is to work on one side at a time. OK. But since the replacement support braces are one long piece (from the left to the right sides) I can't picture how I can fit, adjust and replace the left side of the front support brace while the right side of the brace dangles. One Chevelle-head suggests cutting and then re-welding during the final weld-up step. Wouldn't this compromise strength...I mean, why aren't they sold in 2 or 3 pieces in the first place?

2. In order to keep the body from collapsing when you remove the floor, sevt_chevelle suggests using cross-braces. Anyone have advice as to what steel works best (i.e., 1/8"angle iron?); exactly where they should be welded to the inside walls of the car; do the doors need to be involved in this crossbracing idea? Also, won't the cross-braces get in the way of the poor sap (me) who's trying to cut out and replace the floor pieces?

3. Anyone know about where to buy a rear support brace? The usual suppliers have the front and middle, but the only place where I have rust through in a support brace is my right rear one. Any thoughts about having a shop fabricate something that will do the job if I can't locate the brace?

4. Should I expect to do much welding from underneath? I have only limited access time in a shop with a lift, but if you think it would really make the job go better (stronger welds, more efficient use of time, etc.) then I might be able to roll it onto the lift during those steps that would benefit from it.

5. I have never separated a car body from its frame, although in retrospect I wish I had planned for a body-off restoration. But I have limits in my workspace. I've read the many posts, but I am still confused about the 4x4 board, etc., since I've never seen it done. With the car on the ground on its wheels, do you remove the body mounting bolts (which ones? all of them on the same side you're working on?) Then, what do you do that causes the body to separate from the frame (I can't see taking a crowbar to it)? Once you get them about 4 inches apart do you slip three short pieces of 4x4 into the gap and lower the body back down on teh 4x4's? Where's the risk of misalignment, since when you're done you're using the same body mounting holes for your bolts? Wouldn't this be a good time to replace the old, worn body bushings?
Sorry for the long and many questions, but I'm hoping that the answers to these will become the definitive procedure for floor pan and support replacement in a convertible!

I'm in the middle of replacing the floors on my 70 right now, I'll try and help you as much as I can. From everyone I've heard, in order to replace the braces the body has to come off the frame a few inches. If the rest of the car is as rusty as your floors, this could be trouble. Frozen body mount bolts are a big pain. The convertible body may be reinforced more than a hardtop and may not require as much bracing to prevent flexing, but I havent heard anything about that before. I havent seen any companies that advertise a rear seat floor brace, it may be time to fabricate your own. I havent been doing any welding from underneath. I've welded solid around the top edge and spot welded to the floor braces. That seems to be very strong and I think it will hold up fine. I think you should check out the paddock's floors. They sell everything in a kit. It comes with all the floor pans you'd need, but you'll have to buy the braces seperatly. If I were you, I would try as hard as i could to save the braces. The time and work required to save them may still be less the the headache of trying to replace them. Dont expect to have this job done quick, it requires LOADS of time and patience. Good luck. Hope I answered some questions, just ask if you have any others.

------------------
1970 Malibu
Under Restoration

Ok to answer a few questions since its past my bedtime the first is YES you need to remove all of the body mount bolts. I had my car the ground with all bolts removed. Used two portapowers or big floor jacks and lifted the body up off the frame. I placed the powers under the rockers on both sides to lift the car equally. Once the car was high enough I slide 4x4 under the body that went the length of the frame and then some. So when the car was dropped down the rockers rested on the 4x4s. Placed a 4x4 right under the cowl, middle of car and right before the rear wheel well.

You are right on you want to work one side at a time. The deal on the braces is you replace one full brace at a time. Carefully remove one brace from the floor and from inner rocker. drill out the spot welds dont just cut the brace out with a torch and a section of floor. You need that floor to help position the new brace so you know its correct. Once its removed fit the new brace to old floor. You might need to tweak the brace sightly so it fits nice and snug along the floor and both sides of the rocker. You fit one brace at a time so you know that the brace fits the orginal floor(eventho you are replacing it) this way you know the brace is placed correctly because it fits the floor. Once that brace is done do the middle brace then the back.

You should only tack weld the braces to inner rockers at this time dont fully weld them up as you might need a slight adjustment later. Also hold the braces up tight to the floor at this time with sheet metal srcews and maybe a few tack welds here and there.

Your chevelle head's idea of cutting them into 2or 3 pieces is bad one. Fit the entire brace to the old existing floor.

The 1/8 angle iron will do just fine for cross braces. When I did mine I didnt use cross braces but mine was a hardtop not convert. Ive seen cars that have collasped because someone cut the floors out, so thats why I suggest the cross braces on convert but on hardtops its a bit overkill. As for placement I can mock up some pics and send them tomm.

The rear brace no one repops that part but email me I have one.

If you do all your welding first from the topside after everyhting is done, then you could put the car on a lift and do the underside if need be.

I too bought my floors and braces from the paddock for one simple reason I needed the tranny tunnel and only they oofered one that included it. It would be easier to replace that way and not have two seems going down the tranny tunnel. My braces could have been saved but I decided to replace them as well. Fitting the braces is not hard at all if you do one at a time and fit it to the floors. I have some pics on the link below not the greatest but it might give ya an idea. If not not be afraid to ask since this aint my first rodeo...Eric

------------------
1970 chevelle
1970 chevelle SS455 not a typo its a BUICK BABY
1949 and 1972 chevy trucks
http://briefcase.yahoo.com/bc/sevt_chevelles

I replaced my 65 convertible floor with full length pans, one side at a time before bracing it and lifting it from the frame. I welded top and bottom. Pics of the entire process on my website.

------------------
http://webpages.charter.net/65chevelle/

sevt_chevelle has the right answer. Before I was planning on doing a full resto I was going about it the same way sevt_chevelle listed. On the bracing, 1/8 angle iron is fine. I attached mine on the upper door hinge bolts and the quarter panels, but I was replacing those after the floors. I've been told you can bolt onto the rear window regulator bolt holes. I have some picture on how I did it on my on going restoration link under my name.

------------------
Jamie
67 Malibu Convertible, 2nd Owner since '78
Bonner Springs, KS
A.C.E.S # 4806
N.C.O.A # 5322
67 Malibu Convertible (http://www.chevelles.com/showroom/ragtop67malibu283.jpg)
on going restoration (http://photos.yahoo.com/bc/ragtop67malibu283/lst?.dir=/Chevelle&.src=ph&.order=&.view=t&.done=http%3a//photos.yahoo.com/)

[This message has been edited by Ragtop67Malibu283 (edited 02-14-2003).]

www.goodmarkindustries.com (http://www.goodmarkindustries.com) has full floor pans. (toe panel to front of rear seat)

They are *now available* with the tranny tunnel included.

Too late for me, I had to buy the left and right sections, then build a tunnel from sheet metal.

------------------
Don
1969 Chevelle 2dr. project in progress.

Hey guys ....... This a convertible.The body has to be stabilized before the lifting off the frame.

I'm thinkin if the floorpans and supports are going to be replaced,the body will have to be squared up before lifting or a body/frame fitting will be a problem.You will end up with a /_\ sagging center section once it is lifted. The striker and hinge assm. on the doors is not enough.

E-mail me and I'll show you a simple solution to the problem.I'm assuming you have a welder,and about 70.00 to build a support.