2014 GMC Sierra Manual Transmission Swap w/ Magnuson 2650 Supercharger

Truck

Sep 25

Project Overview

This Sierra showcases one of KTR’s most ambitious in-house builds: the first known manual-transmission swap in this body style. What began as a transmission conversion has evolved into a complete OE+ package with a forged L83, Magnuson 2650 supercharger, custom exhaust, and refreshed exterior. Validated on our Mainline Hub Dyno, the boosted/manual combination delivers 608 whp with the durability and drivability expected from a factory-clean integration.

Specs
      Platform:     2014 GMC Sierra
      Engine:       Forged L83 · Rebuilt heads · Magnuson 2650 · Nick Williams 103 mm TB · Custom 4” intake
      Drivetrain:   Factory-based 6-speed manual swap
      Brakes:       Factory
      Wheel/Tire:   Voxx ES3 24x10 285/40 R24
    

      Audio & Connect:Factory OEM
      Interior:     Sound deadening · Thermal insulation
      Baseline:     281 HP / 354 dFtLb
      Final Output: 608.9 HP / 520.6 dFtLb
      Dyno:  Mainline ProHub Dyno
    

Engine, TRansmission, & Exhaust

The factory L83 was machined by Golen Engine for forged internals and the heads were rebuilt, then the engine was assembled in-house at KTR. Airflow is handled by a Nick Williams 103 mm throttle body and custom 4” intake feeding the Magnuson 2650 supercharger, giving the platform the headroom for reliable, repeatable power.

Exhaust flow was upgraded with Stainless Works headers into a Quick Time Performance cat-back, custom-fabricated for this application by ZMD Fabrication. To harness it all, the truck was converted to a 6-speed manual transmission using OE-based components—a first for this body style and nearly indistinguishable from a factory option.

Interior & Exterior

Inside, the cabin was stripped to install sound deadening and thermal insulation, improving comfort and usability while keeping heat and noise in check.

Outside, Restoration Motors refinished the new front-end sheet metal, pairing a 2016–2018 front bumper with a 2500HD hood to match the truck’s updated capability with a clean, modern look.