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Thread: Looking for advice before cutting out floor pan

  1. #1
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    Looking for advice before cutting out floor pan

    Hey guys, I wanted to pick your brains here as this is my first time cutting out a floorpan and replacing it. I have multiple questions here, and would love to hear feedback on any or all of them before I start cutting.

    Incase people aren't familiar with my build, its a 56 pontiac safari (its very similar to the nomad from the firewall on back) and I will be putting in a chevy floor pan


    First question,

    I was told by a local guy that I should have braced the body while its resting on the ground and not on jack stands. I understand why you would want to do this with a unibody (a lot of dead weight from the suspension hanging from the body). But these cars rest on the frame primarily and the only points remotely connecting the body to the suspension are at the shock absorbers. There is a brace, but that brace is tied into the frame. My shocks are totally shot, so I'm not sure it would even make much of a difference. What do you guys think, should I drop it to the ground, cut out the braces and re-do them?

    Here is where the shocks on the rear suspension attach to the floor pan, its pretty much right at the seam between the floor pan and tail pan.






    So my second question is for ideas to pull the body off the frame. My floor is in really bad shape, so I don't want to use any of the floor pan braces even temporarily to remove the frame. Initially I was going to put the car on my rotisserie to cut the floor out, I thought it would make access easier so I could repair and replace adjacent panels, raise and lower body on the frame, etc. But I'm realizing it's probably going to be more work than its worth.


    The rear body mounts are located under the tailgate are attached to a brace that runs the full length of the tailgate, and also ties in the inner rear quarters. My thought was to weld 1/4" plates to both ends of this brace and use it to support the body in the rear. I would either lift the body with a jack, or loosen the body mount bolts, place blocks or jacks at either side, then slowly lower the frame out from underneath it. My rear most body mounts have some heavy rust on the lower portion of the mounts, so I'm somewhat leery of using those.

    Here is the drivers side brace / body mount





    Passenger side rear brace. The braces look pretty rusty, but they still feel solid.




    My next question is about lifting the front end. I was planning to lift it from the body mounts on the front cowl, with an engine hoist, chains, and spreader bar. Is this the best place to lift?

    Firewall



    Thanks in advance for any help, I'm open to any and all ideas for removing this body.

  2. #2
    Registered Member chevynut's Avatar
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    Quote Originally Posted by 56Safari View Post
    First question,

    I was told by a local guy that I should have braced the body while its resting on the ground and not on jack stands. I understand why you would want to do this with a unibody (a lot of dead weight from the suspension hanging from the body). But these cars rest on the frame primarily and the only points remotely connecting the body to the suspension are at the shock absorbers. There is a brace, but that brace is tied into the frame. My shocks are totally shot, so I'm not sure it would even make much of a difference. What do you guys think, should I drop it to the ground, cut out the braces and re-do them?
    I wouldn't worry about it. Your bracing is only going to get you "close" imo, and you'll fit the floor to the body. The body will still flex some after removing the braces. When putting my quarters on I put the jackstands under my frame where the load is carried, to make sure the body wouldn't flex when it's on the wheels. But it still will some.

    The shocks have no effect on loading the frame. It's the springs that carry the load. Whoever told you that doesn't seem to understand it.


    So my second question is for ideas to pull the body off the frame.


    Here's what I did:

    20150317_004.JPG

    20150304_003.JPG
    56 Nomad, Ramjet 502, Viper 6-speed T56, C4 Corvette front and rear suspension


    Other vehicles:

    56 Chevy 2-door BelAir sedan
    56 Chevy 210 4-door sedan
    57 Chevy 210 4-door sedan
    1962 327/340HP Corvette
    1961 Willys CJ3B Jeep
    2001 Porsche Boxster S
    2003 Chevy Silverado 2500 HD Duramax
    2019 GMC Sierra Denali Duramax

  3. #3
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    I agree with Cnut, putting the braces in with the frame on jackstands is not really much different than with the tires on the ground.

    Lifting the body as Cnut did it will work fine. A couple of brackets made from 3/16" x 2" bar mounted to the firewall where the hood hinges attach is an alternative to using the cowl support bolt holes, and won't require a spreader bar. I've also lifted the front of the body with straps looped through the cowl supports but found that the straps like to "dig in" to the cowl support/firewall joint and are hard to remove.

    Using your frame as a jig to install the floor is the best way to do that. Set the new floor on the frame with new body mounts. Lower the body onto the floor and frame and start lining things up. You don't have to complete all the welding in this step, just enough to make sure things won't move. Then you could put the body on a rotisserie and finish up.

  4. #4
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    [QUOTE=chevynut;45545] The shocks have no effect on loading the frame. It's the springs that carry the load. Whoever told you that doesn't seem to understand it.

    Thanks Laszlo,

    No one told me that the shocks would carry load to the floor pan. After the guy mentioned that I should have braced the car while it was sitting on the ground, I went around to see if there were any potential areas where the suspension could even possibly affect the floor pan. I was just noting that this is the only area I saw where it would even be remotely possible, everything else bolts directly to the frame rails. I kind of figured I was worrying about nothing but I just wanted to clarify before there's no turning back. I'm pretty sure this guy only works on unibody cars. I can sort of see where he's coming from if the suspension is hanging like dead weight when you're replacing the floor pan on a unibody, but then again I've never done it so I could be dead wrong.

    How you did the front is exactly what I had in mind. I'll see if I can pick it up from the tailgate hinge are in the rear. My hinges are heavily rusted in and under that area and I haven't had any luck getting them out. The metal holding the nut plate for the tailgate has pretty well rusted away. I'll take another stab at removing the hinges tonight and report back. I may have to drill them out. .


  5. #5
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    Thanks for the help guys, I got the hinges drilled out and the metal looks pretty solid underneath. I should be able to pick it up from there. I guess I just keep overthinking things because I'm afraid to cause any additional damage... Shoulda had those hinges out months ago.




  6. #6
    Registered Member BamaNomad's Avatar
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    Your 'safari' frame is like a rock compared to our Nomad frames (Pontiacs have the huge X member similar to Chevy convertibles)! I like the approach suggested by Rick... Good luck... keep the photos and posts coming!

  7. #7
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    Quote Originally Posted by BamaNomad View Post
    Your 'safari' frame is like a rock compared to our Nomad frames (Pontiacs have the huge X member similar to Chevy convertibles)! I like the approach suggested by Rick... Good luck... keep the photos and posts coming!
    Yeah, those frames are beefy... I spent a lot of time trying figure out how to keep the frame, box it in, and use the C4 corvette suspension.. in the end I felt it was simpler to ditch the Pontiac floor and use a bel air frame. They don’t re-pop these Pontiac floors (as far as I know, and I looked long and hard), and the frame rails are way to wide to fit the rear corvette suspension... I think I will try using the brackets on the hinge holes, it appears to be more sturdy in that area. my toepanel is pretty rusty, and the hole for the steering colum is quite large

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