Pro-Line 12mm Big Bore Pro-Spec Rear Shock (2) (Pre-Assembled)

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Pro-Line 12mm Big Bore Pro-Spec Rear Shock (2) (Pre-Assembled)
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This is a pack of two optional Pro-Line 12mm Big Bore Pro-Spec Rear Shocks, designed for Short Course Trucks and other 1/10 scale off-road applications. The next generation of Pro-Line Shock Technology has arrived - The Pro-Line Pro-Spec Shocks! These shocks come nearly ready-to-go; just add the shock fluid of your choosing and hit the track.

The Pro-Spec Shocks are a 12mm Big Bore design with a Single Low Friction X-Ring Seal. The Pistons and Shaft Guides are made from Silky Smooth White Delrin for Low Stiction and the 3.5mm thick Shock Shaft is Hard Chrome Coated, just like full scale racing shocks. Also featured on the Pro-Spec Shocks are easy access Bleeder Cap Screws that allow for consistent shock bleeds and builds every time.

Each pair of Pro-Spec Shocks includes 3 different piston options (1.4, 1.6 & 1.8) and a blank piston for drilling to a custom size. Custom Shock Tightening Tools and optional shock limiters are also included. Optional Pro-Spec Springs are available separately. Upper and lower shock pivot balls are included so you can fit a wider range of vehicles right out of the box.


  • Smoothest Shocks Pro-Line has ever made
  • Pre-Assembled, Just Fill and Go
  • 12mm Big Bore Technology
  • Single Low Friction X-Ring Seal
  • Silky Smooth White Delrin Shaft Guides and Pistons
  • Optional Pistons and Limiters Included
  • Easy Access Bleeder Cap Screw
  • Hard Chrome Coated 3.5mm Shock Shaft
  • Optional Spring Rates available separately
  • Will work with Hardware kit (PRO6063-05)
  • Also available in a kit form (PRO6308-01)
  • Pro-Spec (PRO6308-30) Front Shocks also available


  • Pro-Spec Front Shock Lengths (No Limiters):
    • Extended: 100mm
    • Collapsed: 68.5mm

    ProLine Shock Data


  • PRO6308-02: Pro-Spec Delrin Piston &? Guide Tree
  • PRO6308-03: Pro-Spec Plastic Tree
  • PRO6308-04: Pro-Spec Shock O-Rings
  • PRO6308-05: Pro-Spec Shock Hardware
  • PRO6308-06: Pro-Spec Shock Cartridges
  • PRO6308-08: Pro-Spec Rear Shock Shafts
  • PRO6308-10: Pro-Spec Rear Shock Bodies
  • PRO6308-18: Pro-Spec Rear Yellow (Medium) Springs

This product was added to our catalog on April 10, 2014

Wednesday, Oct 31 2018 (about 5 years ago)
Pro-Line 12mm Big Bore Pro-Spec Rear Shock (2) (Pre-Assembled)
Just got into dirt oval racing this year, took my old slash and ran half the season on these shocks that have been bashed around for the last two years without checking or rebuilding the shocks. After I rebuilt them at the halfway point found they still had nearly full fluid in them. Best shocks by far, worth every penny. At first glance they may seem overpriced, but let me assure you they are perfectly priced for what you get and what I'm still getting out of them.
mike sorchy
Verified Owner
Saturday, Dec 10 2016 (about 7 years ago)
Pro-Line 12mm Big Bore Pro-Spec Rear Shock (2) (Pre-Assembled)
I love these shocks on my sc10 what a improvement from the older factory team shocks(not 12mm) and just add oil and go . i used 30w all around as a base and right off the bat a huge improvement . 5 stars
Verified Owner
Friday, Jan 30 2015 (about 9 years ago)
Pro-Line 12mm Big Bore Pro-Spec Rear Shock (2) (Pre-Assembled)
Bought these because I was too lazy to put the other sets together. I must say I really enjoy how easy they were to fit on and the ease of stiffening your shocks. If you race you gotta have some big bore shocks!
Luis Campbell
Verified Owner
Saturday, Jun 19 2021 (about 2 years ago)
Pro-Line 12mm Big Bore Pro-Spec Rear Shock (2) (Pre-Assembled)
beware. shock rebuild kit is discontinued. The plastic around the top pivot ball broke on one of mine making both useless.
David Núñez García
Verified Owner
Friday, Aug 23 2019 (about 4 years ago)
Pro-Line 12mm Big Bore Pro-Spec Rear Shock (2) (Pre-Assembled)
Incredible shock absorbers, I have them mounted on the back of my scx10 ii, in the front I have those of 90, they work very well and do not lose oil