'70 'Cuda Frame Rail Replacement

[AARGeister]

Howdy,

I have to replace both the rear frame rails and the trunk floor on a '70 'Cuda.  Would it be easier to put in the frame rails first, after drilling through the spot welds on the frames?  Then I could lay in the trunk floor and from the bottom of the car, mark the holes for the spot welds through the frame onto the trunk floor.

Also, how can I do this on some sort of a roitisserie system?  I can't attach a roitisserie the normal way to the frame, obviously.

With a MIG welder, do I need to lay in a beam when putting in the frames, or should I tack weld the frames like I would quarter panel skins and the trunk floor?

Thanks!

[HemiDog]

If you have some trunk left, I would replace the rails first.  It will help you line the rails back up in the original positions.  You should be able to weld the rails to the rear cross brace, the shock mount brace, and hopefully some of the floor under the rear seat.  Then I would replace the trunk.

I had to replace the drivers side, rear and I ended up building two wood stands that were about three feet tall and would about four feet across to support the car in front of the rails.

[FeO2 bucket]

I have to do this as well but only the drivers side rail . Trunk pan . Trunk extensions. Quarter skins, you all know the drill. I have to replace it to just where it bends to go under the rear seat. Does anyone know of a source for the rail that is not a frame cap? I don't want to trap old rust under the new part. And did I see on Musclecar on spiketv that they used a replacement rail that wasn't a cap on their project challenger?

[AARGeister]

I appreciate the responses!

FeO2, I saw that the Paddock sells them.  You could check with them or shop around for a better price.

HemiDog, I don't have much trunk floor left but I think I can still draw a thin outline of the current frame onto the floors.  Do you have any pictures of your stand?

[360 'CUDA]

Check out this guy on E-bay,,,  He seems to have lots of frame parts


http://cgi.ebay.com/ebaymotors/1970-70-1971-71-1972-72-Cuda-Challenger-Rear-Frame-Rail_W0QQitemZ330011287794QQihZ014QQcategoryZ10076QQrdZ1QQcmdZViewItem

[HemiDog]

I just went through all my pictures and not one picture of the stands!  Not even in the background!  That kind of irks me. 

This might not help much, but each one was built like building a house wall that was 3 feet tall and in a "T" shape for support.  I used 2x6 lumber to make sure it would support the back of the car.

Try not to let the back of the car hang.  Anything you can to to keep the car from flexing will be worth while. 

[AARGeister]

So, it's like building an island counter for a house.  How did you keep the car from hanging if it was on the stands while you replaced the frame rail?

I'm looking at using a Body Tilter but I can't justify the cost yet.

[HemiDog]

I only had to to one rail.  To help keep it from flexing, I had a stand under the other rail and a 2x4 in the rear corner of side of the one I did replace.  There are probably better ways to do it, but I didn't feel that I really need to build or buy a full out frame jig.  Would be very nice though!

[Mike71Cuda]

I had to do both frame rails trunk floors extension qts the whole enchilada. I did this before they had frame rail extensions, so I did it from a donor car. Depending on how far forward you have to go will determine on how to it. I put the car high up on jack stands (rear stands in front of rear tires) then I measure off a couple of 2x4s of the height with everything intact. Then I started to hack away at trunk floors. truck floor pretty much lines itseld up with shock tower humps, so not too much with regard to wondering placement. once I cut the floors out I took a pan head screw to top of 2x4 and wedge body lip (welding surface that floors will stitch to). Now that back of car was supported with 2x4s (left and right) I hacked off rotted frame rails. It is a little freaky when you do this, you say to yourself di dI just ruin this car? Measure everything as you are going. I found teh qtr extensions to be the worst part of teh project, tough to have a point of reference, the otehr stuff seemed easy. Let me kow if this sounds confusing I will see if I can find some pics of what I did tonight, good luck.

[AARGeister]

I think what I am going to do is weld some steel tubing ON the car outside of the frame rails, and then build a rotisserie to hook up to the tubing.  Then I can work on the frames while the car is on the rotisserie.

It will be so much nicer to have the car on its side or upside down when working on the rear frame rails.