3006-982 through your local cat dealer. those are pistons kits.
some other info i have found usefull.
SPEEDWERX 800 SX Engine/Pipe Package
•Torque Specifications
–Head Bolts18 Ft/lbs.
–Cylinder Base Nuts22 Ft/lbs.
–Power valve Bodies8 Ft/lbs.
–Exhaust Flanges18 Ft/lbs.
•Carburetion
–CarburetorsMikuni Flat slide 40mm
–Main Jet450
–Pilot Jet60
–Needle9EH11-60
–Slide3.0
–Reed ValvesV-Force Delta 3
•Clutching
–Clutch WeightsS2 (69.5 Grams) (Optional R2 67.5 Grams)
–Primary SpringRCS 8005 (165/305 # Titanium)
–Team Driven Clutch70-50-.46 Cam
–Driven SpringTeam 160/260
•Engine
–Displacement795cc
–Bore85mm
–Stroke70mm
–Fuel RequirementArctic 114
–Oil RequirementArctic APV
–Mix Ratio18oz : 5 Gallons
•Break In32oz : 5 Gallons
–Cylinder HeadAC805-31
–Squish Clearance(.050”-.052”)
–Piston/Cylinder (Clearance)(.005”-.0055”)
–Piston/Cylinder (Service Limit)(.008”-.0085”)
–Operating RPM7900-8100 (Holes hot/Acceleration 8100-8400 (On Track/Hot Pipes)
•Ignition
–Ignition Timing Check24 degrees @ 2,000-3,000 RPM
–Spark PlugsNGK BR9ES OR BR9EYA
–Spark Plug Gap.024”-.028”
