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    Results 1 to 9 of 9
    1. #1
      Join Date
      Aug 2007
      Location
      Denton Texas
      Posts
      1,236
      Country Flag: United States

      18x12 with 335 in a Grand National with frame notch rolled fender

      Hey Fellas, got some questions. Im a regular on Protouring.com and love the whole look and feel of a PT car, and I was like hell I have a GN why not do it to that car . So I ordered a full QA1 suspension with coil overs and am getting ATS spindles, I ordered the Baer front and rear brakes, Im going to keep the 8.5 just rebuild it, and than I was on to rims and tires. I want to run a CCW classics 18x12 with a 335 30 18 in the rear. I know I will have to notch the frame, I have looked though the forum post and there is some good advice, but I cant seem to find anyone who actually has ran a 18x12 with a 335, as i might need advice for backspace. I plan on rolling the fender, so that will buy a little, and with the frame notch, Ive looked at the older post, looked at gbody forum, the grand national forum, and see some advice, but nothing real recent. Who make a complete kit, meaning the notch plates, backing plates, on the back side of the frame, the tubing that reinforces across the frame(I have seen as many as 3) Im trying to make as rigid as can be, as I have read through the forum post of the dreaded fender buckling. I will have the body off the frame, so I can do the notching and reinforcing properly, plus Im having the frame powder coated when done. this is the beauty below. I plan on running a L86 with CnC heads, a cam, LT4 blower and a TR6060...I know I can buy a frame, there are several out there, but the cost makes it a no go...

    2. #2
      Join Date
      Aug 2008
      Location
      jacksonville,fl
      Posts
      970
      Country Flag: United States
      Southside machine is one place that has a notch kit.
      https://southsidemachineperformance....rame-notch-kit
      Never personally notched a frame or widened inner wheel wells, but I know 335's fitting in there would be tight with optimum backspacing.
      May want to check with Ben @ speedtech (SRD art on this forum) He designed some front & rear frame bracing on his personal wagon project years ago I think they are making.

    3. #3
      Join Date
      Aug 2007
      Location
      Denton Texas
      Posts
      1,236
      Country Flag: United States
      Quote Originally Posted by jlcustomz View Post
      Southside machine is one place that has a notch kit.
      https://southsidemachineperformance....rame-notch-kit
      Never personally notched a frame or widened inner wheel wells, but I know 335's fitting in there would be tight with optimum backspacing.
      May want to check with Ben @ speedtech (SRD art on this forum) He designed some front & rear frame bracing on his personal wagon project years ago I think they are making.
      Thanks, I will reach out to them, if I have to move frame that might need to be.. we have to have 335's on a Grand National..

    4. #4
      Join Date
      Aug 2008
      Location
      jacksonville,fl
      Posts
      970
      Country Flag: United States
      I'd shoot for a little extra breathing room to be safe with tire & vehicle variances. Don't need to justify to me wanting room for wide tires.
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      Couldn't afford a Schwartz frame myself, going my own route. Prefiguring will be a big thing here. I'm not a frame expert, but I cut & weld. If need be, I'd think with frame laid down on something to jig it & keep it straight, if need be you could make the inner rail the new outer & double up the backside with new metal along with some extra reinforcements you'd have to cut out yourself. Good quality thin metal cut off wheels & a higher power 4.5" grinder can cut through 1/8" metal reasonably quick with no plasma slag to have to grind off.

      Here's a link to Ben's pumkinator thread. Frame mods begin at page 13. This is of course a wagon, but last I remember he only had 305's or 315's out back with these mods & we had spoke about fender flares as he wanted 335's now.
      https://www.pro-touring.com/threads/...-getter/page13

    5. #5
      Join Date
      May 2011
      Location
      Chippewa Falls, WI
      Posts
      290
      Country Flag: United States
      UMI has a frame notch kit for g bodys. They are on 315's on their green machine. YMMV on the body side of things, and it would be best to measure. You would need 13.5 inchs wide to fit a 335. Do not rule out a 315. Depending on how serious you are getting with handling over looks, there is not always as much to be gained in performance with a 335 unless the front grip capabilities match for a grip neutral car. What front tires are you planning?
      Justin N.

      1966 Chevelle
      1992 GMC Typhoon
      1989 Jeep Wrangler CJ 6.0 Twin Turbo
      1981 Jeep CJ7

    6. #6
      Join Date
      Aug 2007
      Location
      Denton Texas
      Posts
      1,236
      Country Flag: United States
      Quote Originally Posted by Typhoon1015 View Post
      UMI has a frame notch kit for g bodys. They are on 315's on their green machine. YMMV on the body side of things, and it would be best to measure. You would need 13.5 inchs wide to fit a 335. Do not rule out a 315. Depending on how serious you are getting with handling over looks, there is not always as much to be gained in performance with a 335 unless the front grip capabilities match for a grip neutral car. What front tires are you planning?
      rivals... I think a 18x12 would look great..

    7. #7
      Join Date
      Aug 2008
      Location
      jacksonville,fl
      Posts
      970
      Country Flag: United States
      I still can't think of anyone with just the traditional frame notch & no major body mods having wider than a 315 in the back, so you will need a little next level effort to modify the factory frame.
      Up front, 18 x 8.5's took fender inner lip flattening & removing outside of factory wheel wells to run on mine, so 12's up front would take some major framework & swaybar work to tuck in & still have a turning radius left.
      Not being discouraging, just saying, gotta pay to play.

    8. #8
      Join Date
      Jan 2015
      Location
      Raleigh NC
      Posts
      52
      Country Flag: United States
      I am running a 335 nitto nt555r on my gn. The bfg's are to wide for my car, i have a set on there now and i will be taking them back off because i don't want to raise my car up. I have fikse 18x11.5 wheels and notch the frame just past the weld seem. In order to fit that rival's you will need to notch the frame all out but the backside only and roll the lip. I did mine myself and did a lot of reinforcement back there unlike these cheap kits you are talking about. If you use just these kits you will be doing body work in the near future if you have any power at all. I'm pulling 1.35's 60ft's with a pro touring susp. On my car at the drag strip and have not had any problem so far.

    9. #9
      Join Date
      Aug 2008
      Location
      jacksonville,fl
      Posts
      970
      Country Flag: United States
      Another thought to this. I'm not a gn expert , but saw on one of the sunday morning tv shows that the GNX models had wider flares. Hmmm?
      As stated above cutting out completely to the inner rail sounds about right to me for fit.
      https://www.google.com/search?q=buic...hrome&ie=UTF-8
      I apologize ahead of time to Don if I'm giving him more bodywork.







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