JE Piston Kits
TRX 400 1996-2007/85mm/10.5:1/397cc
TRX 400 1996-2007/86mm/10.6:1/406cc
TRX 400 1996-2007/87mm/10.8:1/415cc
TRX 400 1996-2007/89mm/12:1/435cc

Wiseco Piston Kits
TRX 400EX 1999-2007/85mm/10:1/397cc
TRX 400EX 1999-2007/85mm/11:1/397cc
TRX 400EX 1999-2007/86mm/11:1/406cc
TRX 400EX 1999-2007/87mm/11:1/416cc
TRX 400EX 1999-2007/88mm/11:1/426cc
TRX 400EX 1999-2007/89mm/12.5:1/440cc

Dynojet Jet Kits
TRX 400 Foreman ATV 1996-2002 Stage 1
TRX 400 Rancher 2004-2005 Stage 1
TRX 400EX ATV 1999-2007 Stage 1/2

K&N Engineering - High Performance Air Filters
TRX 400 1999-2002

Dynatek
Dyna FS Offroad Ignition - TRX 400EX 1999-2003
Dyna FS Offroad Ignition - TRX 400EX 1999-2003/Programmable
Dyna FS Offroad Ignition - TRX 400EX 2005-2006/Programmable

Kibblewhite Precision Machining
Titanium Retainer & Valve Spring Kit - TRX 400 1999-2005
Titanium Retainer & Valve Spring Kit - XR 400 1996-1999/EX 400
Valve Guide - TRX 400 1999-2005/Ampco 45/Standard Diameter

Camshafts
TRX 400EX 1999-2005/.350" @ 256 Int/.345" @ 256 Exh/.050" - Hardfaced
TRX 400EX 1999-2005/.378" @ 250/.050" - Hardfaced
TRX 400EX 1999-2005/.385" @ 272 Int/.370" @ 270 Exh/.050" - Hardfaced - Race Profile

Cometic Gaskets
Top End Kit - TRX 400EX 1999-2007/86mm Bore/Spring Steel Head Gasket
Top End Kit - TRX 400EX 1999-2007/89mm Bore/Spring Steel Head Gasket

Carrillo Industries
Connecting Rod - TRX 400EX/H Beam Style Chrome-Moly Steel/Standard