If you’ve got a 1999-2003 7.3 Powerstroke and you want a true drop-in turbo upgrade that spools quick and supports real injector growth, the KC Turbo KC300X Gen 3 Stage 1 turbocharger is built for exactly that. It’s rated to support up to 205cc/30% injectors, and two options are available: one for early 1999 trucks, and another for 1999.5-2003.

 

Fitment

• PN 302676 Fits: Early 1999 (e99) 7.3L Powerstroke pickup trucks.
• PN 302523 Fits: 1999.5-2003 7.3L Powerstroke pickup trucks
• Neither will fit OBS without modification.
• Vans can work, but expect intake boot/downpipe fitment tweaks.

 

 

What makes the Gen 3 KC300X Stage 1 different

• This turbo is built around modern air flow and durability upgrades
• Gen 3 7x7 SXE-style compressor wheel with upgraded aerodynamics for quick spool
• 0.70 A/R ported compressor cover with improved map groove / anti-surge ring / volute shape
• 0.91 A/R turbine housing designed to spool faster and carry more top-end than the older 0.84/1.0 options
• 200% larger thrust + journal bearings, thicker turbine shaft, redesigned bearing housing, and a steel thrust insert to improve stability and reduce fatigue at higher boost/HP
• High-flow non-EBPV outlet flange and a redesigned wastegate actuator for better boost control
• Includes all gaskets/O-rings required for standard install, and an upgraded 4" intake boot

 

What owners usually feel

The most common “seat of the pants” difference is earlier boost and better response—the turbo starts working sooner instead of waiting for higher RPM and/or load. The product reviews on our listing echo that: “immediate boost,” “night and day,” and “very responsive.”

 

Install reality:

Step by step: Remove the turbo, discard the turbo-to-pedestal O-rings, remove the pedestal (if needed/leaking) and discard pedestal-to-block O-rings, clean the mating surfaces, install new O-rings, reinstall the pedestal and torque the pedestal bolts to 18 ft-lb, reinstall the turbo and torque the turbo mounting bolts to 18 ft-lb, align the up-pipe collector pin to the turbine housing and tighten the Marmon clamp to 60 in-lb, then start and check for leaks.

Full instructions for general 7.3 turbo replacement can be found here: https://www.riffraffdiesel.com/content/RESOURCES/Riffraff_Diesel_Turbo_Instructions.pdf

 

“Do it once” add-ons we recommend:

• Bellowed 321 stainless up-pipes (E99 HERE, and 99.5–03 HERE) to replace leak-prone donut-gasket style pipes (the turbo can’t spool if it’s being fed by a leaky exhaust).
• PHP Hydra Chip if you want tuning you can actually see/control (15 tune slots + No-Start + Bypass).

 

Last note:

If you want a ’99–’03 7.3 drop-in turbo upgrade that’s built around quicker spool, stronger internals, and clean fitment, the KC300X G3 Stage 1 is the sweet spot for all driving styles. Daily driving, heavy and light tow.