SoCal Diesel Billet Duramax Main Girdle



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SoCal Diesel Billet Main Girdle

Fits 2001-2016 6.6L Duramax


*REQUIRES a 1/2" longer main stud kit. Sold Separately* 

The Duramax engine suffers from main cap movement at high power levels. Even with ARP main studs and cross bolts, we have seen evidence in the bearing wear, of the cap flexing towards the front or the rear of the engine. The SoCal Diesel Billet Main Girdle is a solution that provides structure to the top of the main caps, linking all of the main caps together, as well as linking the main caps to the pan rail.  


  • Blanchard ground
  • 1 piece design for ultimate strength, rather than an inferior, cheaper to manufacture, 2 piece design
  • Precision machined
  • 1/2" thick across the main caps
  • 9mm thick at the pan rail to make sure the oil pan will not interfere with the steering linkage
  • Includes longer oil pan bolts. (qty 20) 8mm x 45mm oil pan bolts, (qty 4) 8mm x 35mm oil pan bolts and (qty 2) 8mm x 35mm oil pump pickup bolts and washers)

SoCal Diesel Assembly Tips:

  • Make sure there is a minimum of .001" clearance between the block and the girdle
  • During final assembly, make sure you install the oil pump and crank trigger wheel before the girdle
  • A thin film of gasket sealer is necessary between the block and the girdle
  • Use the oil pan bolts for alignment purposes when torquing the girdle into place
  • The two bolts between the flywheel cover and the block will not be used


  • Girdles REQUIRE a 1/2" longer main stud kit. The regular ARP main stud kit will not work!
  • Stock main caps can be used with this girdle, but the top of the main caps will need to be machined completely flat with the pan rail.