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6.2/6.5 Diesel 6L80E/6L90E 6 Speed Conversion Kit

6.2/6.5 Diesel 6L80E/6L90E 6 Speed Conversion Kit

Quadstar Tuning LLC

  • $2,250.00
  • Save $225

Everything you need, except the transmission, to swap a true 6 speed automatic behind your 6.2 or 6.5 diesel!  This will work with both mechanical and electronic injection trucks (DB2 or DS4) and 6L80 or 6L90 transmission.

This kit will require the willingness to perform final tuning on your end.


  • PCS transmission communication module with universal wiring harness
  • Base transmission tune file
  • Custom multi-disk torque converter
    • Utilizes proper low stall speed for diesel applications
    • Uses all 6 mounting bolts
    • Weighs in at 20# less than a factory 4L80E converter. This is a HUGE rotational weight savings
  • Bellhousing adapter kit with hardware and dowel pins
    • Provides 360 degrees of support for the 6L bellhousing flange
    • Ensures proper spacing for the included torque converter
  • ARP torque converter bolts
  • ARP flexplate bolts
    • Compatible with stock 6.5L flexplates or our billet flexplate offering
  • 6AN Transmission line adapter block
  • Crank sensor breakout harness for DS4 trucks
  • Wiring instructions
  • Informational documents for transmission selection
  • Informational documents for transfer case re-use or swap compatibility

Benefits of the swap:

  • Fully automatic shifting and torque converter lockup in auto mode
  • Manual tap shift control for upshift and downshift
    • The 6L can hold 100% on deceleration unlike the 4L80
    • Automatic downshifting can be left enabled in tap shift mode
    • If your final gear ratio is still high, you can set it to start in 2nd gear
  • Multiple shift strategies. Pattern A, B, and Tap Shift. I.E. "Tow Haul" mode.
  • Gain 6th gear, an additional overdrive over a 4L80e
  • Torque converter lockup is far more useful due to the better gear spread.  We don't need to wait until 45+ mph to go into lockup like with a 4 speed.
  • Enables you to lower the final gear ratio, if desired, to maximize economy and torque multiplication gains.
  • The end user has full control over programmability/adjustments of shift points, shift firmness, and torque converter lockup. This often isn't the case with a factory 4L80e.

***All features may not be available in some transmissions.  They can be available if you properly flash the TECM calibration in the transmission with GM SPS, however. Work with your transmission builder during the build to confirm before final assembly. For example, a truck TECM might not have full tap shift capability in some operating systems and flashing a Corvette or similar OS would enable it***

Additional Options available by request:

  • HP Tuners MVPI 2 Interface for tuning the transmission's internal TECM/TCM
    • This is required if you don't already have access to one
  • Paddle Shifter tap shift kit
  • Toggle switch tap shift kit
  • DS4 trucks will require a tune to the factory ECM/PCM to disable factory automatic transmission control and trouble codes.
  • Remanufactured TECMs and SPS programming
  • Tuning support

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