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Reinforcement for Topless Conversion?

Discussion in 'The Garage' started by BigCountryx, Apr 9, 2006.

  1. BigCountryx

    BigCountryx 1/2 ton status

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    Will Square tubing rocker panels be enough reinforcement to the body for the removal of the factory halftop? Seems as though it would be since the 73-75 models only had rocker boxes to add reinforcement didn't they?
     
  2. sled_dog

    sled_dog 1 ton status

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    personally I wouldn't do it without a cage. I've never seen a 73-75 flex up, but I can't believe they are very stiff in any regard.
     
  3. fireplug

    fireplug 1/2 ton status

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    I've been looking for this info for a while. I'd be happy as heck just to see some pics of the factory rocker box. Finding a '73 - '75 up here is tough. Any one, anyone?
     
  4. blazinzuk

    blazinzuk Buzzbox voodoo Premium Member GMOTM Winner

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    okay maybe you can see this well enough to answer your question I don't have a camera right now but will see if I can round one up to take more if you need it the boxes extend all the way to the frame and compared to my bro inlaws 77 and when I had the outsides of them cut off (as in this pic) the body did flex more alot more. the 77 would get flexed out and it was hard to open his doors never had that problem with mine you could also see his fenders get out of alignment but not on mine of course this is all my opinion but it would be pretty simple to build if you are doing the swap
     
    Last edited: Dec 10, 2007
  5. fireplug

    fireplug 1/2 ton status

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    Thanks sooooo much and YES more pics would be great! Thanks again!:bow:
     
  6. dyeager535

    dyeager535 1 ton status Premium Member

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    The problem is that the frame isn't stiff enough.

    I wasn't even aware of the "rocker boxes" on earlier trucks, but it sounds and looks like they were big enough to solidify (at least somewhat) the frame right in the middle where the cab would twist if flexed.

    You could, with a lot of effort, stiffen up the body enough to hold everything in place, but a cage to the frame, as mentioned, would be the way to go. Either that or boxed frame, better crossmembers, etc.

    I had thought/hoped that tying the body to the frame more rigidly (poly bushings) would help strengthen the frame, but it didn't. If anything the body flex didn't lessen, now it's more noticeable as the body is forced to move just as much as the frame. With rubber, there was more "give" at all the mount locations.
     
  7. 73k5blazer

    73k5blazer Unplug the matrix cable from the back of your head Premium Member

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    I ditched my factory body a while back, but the "rocker boxes" being refered to are this:
    a piece of, umm I'd probably say it was 1/8" steel, ran from bottom edge of rocker over to frame (didn't tie to frame) right to left, and from fore-aft it ran from the angled section of the front floor to just behind the front seat, then anlged back up to the floor.
    Sort of boxin in the area of the body where a pickup gas tank would go, a little shorter than a PU gas tank though.
    It was a body stiffener, not a frame stiffener. Without it, with the top off, one could grab the top of the windshield frame and bend the whole windshielf/firewall section back by hand. Well, I could do that on my '73 with the boxes, but mine was rusted very badly.
     
  8. BizeeB65

    BizeeB65 1/2 ton status

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    I've got a 73... I'll try to get pics up of the boxes this weekend.
     
  9. dyeager535

    dyeager535 1 ton status Premium Member

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    Hmm, interesting. Looking at the sole pic, it appeared it went over to the frame.

    Still a bass-ackwards way to do it IMO. Solidify the frame and the problem would have been gone. Then again, it took (GM at least) how many years from '75 to figure out that stiff frames work? 13+?
     
  10. fireplug

    fireplug 1/2 ton status

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    Sounds like the rocker boxes aren't that effective, nor the cage, which leaves boxing in the frame but I've often heard that that often has drawbacks because it tends to crack where boxing in isn't possible? I guess there is no real solid answer to this problem?
     

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