1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

UMI Releases New Product: Rear Frame Notch Kit for the 1978-1988 GM G-Body

Discussion in 'UMI Performance' started by UMI Performance, Feb 23, 2017.

  1. Ace Burt

    Ace Burt Not-quite-so-new-guy

    Joined:
    Jul 23, 2017
    Messages:
    18
    Likes Received:
    8
    Trophy Points:
    3
    What size tires and wheels were able to use afterwards? Contemplating doing this myself.
     
  2. 565bbchevy

    565bbchevy Comic Book Super Hero

    Joined:
    Aug 8, 2011
    Messages:
    4,032
    Likes Received:
    1,042
    Trophy Points:
    113
    Location:
    Michigan
    The largest tire in 15" I have ran was a 295/65 M/T drag radial but they are very tall and I later changed to my current 295/55 M/T's these are on 15 x 9.5 rims with 5.5 backspace, I could go a little wider but I like my tires not to stick out at all.
    If you are going with a larger diameter rim you can get by with wider tires because the section width decreases as you increase rim size.
    IMG_1470.JPG
     
    #12 565bbchevy, Aug 26, 2017
    Last edited: Aug 26, 2017
  3. UMI Performance

    UMI Performance Master Mechanic
    Supporting Vendor Silver

    Joined:
    Jul 9, 2011
    Messages:
    333
    Likes Received:
    46
    Trophy Points:
    28
    Location:
    Philipsburg, Pa
    Hey Guys, getting caught up. Kits are not built to order and are stocked but doesn't mean we could sell more than what we have in stock and need to make a new batch. Also new products sometimes have bugs to work out and we run low quantities in case something isn't right.

    For wheel widths, I can't say what would work for you. But on our car we will be running a 18"x11" with a 315 tire. I would assume this is max and will still be snug.
     
    • Like Like x 2
  4. Ace Burt

    Ace Burt Not-quite-so-new-guy

    Joined:
    Jul 23, 2017
    Messages:
    18
    Likes Received:
    8
    Trophy Points:
    3
    Thanks, I am going to run either 17 or 18" wheels, I haven't decided yet. Would I run the same back set with a larger wheel diameter? BTW, your car looks sweet!
     
  5. Ace Burt

    Ace Burt Not-quite-so-new-guy

    Joined:
    Jul 23, 2017
    Messages:
    18
    Likes Received:
    8
    Trophy Points:
    3
    Thanks, Is there a standard way to measure for clearance? I have never had a car I needed to alter to run bigger tires and wheels so this is new ground for me.
     
  6. Ace Burt

    Ace Burt Not-quite-so-new-guy

    Joined:
    Jul 23, 2017
    Messages:
    18
    Likes Received:
    8
    Trophy Points:
    3
    I got my notch done using the kit. I put a post on the chassis tech forum with a bunch of pics detailing the process and some stuff we did to make it stronger as well and narrow. I don't want my tires to rub but I want as much tire as I can get under it as well. What I am getting for feedback so far is roughly 5.5 backspacing and I just need to measure for clearance when its all back together. Do you have to cut up the fender wells also?
     

    Attached Files:

Loading...

Share This Page