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The TH-2004R is a great overdrive transmission that has received very little attention. While some disagree, it is basically as strong as a 700-R4 and will bolt into virtually any Chevy chassis with few modifications. The TH-2004R has a 2.74 ratio in first gear, which is 10% lower than most transmissions. The overdrive will give a 20 to 30% increase in gas mileage on the road. The TH-2004R is a popular transmission swap for muscle car restorations to add the overdrive option & to update to a modern transmission.

  • PART#GM TH-2004R TRANSMISSION STAGE 1
  • 120-1100Includes: Performance Overhaul with Borg Warner Frictions, High Energy 2nd Gear Band, GN Intermediate Servo, New Overdrive Roller Clutch, MP Calibrated VB and Pump (Increases Clutch Holding Power Capacity, Cooler Flow, and Shift Firmness), New Bushing Kit, New Washers & Bearings, New Low Roller Clutch, Hardened Stator Shaft, and New TCC Lock-Up solenoid & Pressure Switch. Rated @ 350 HP/TQ
  • PART#GM TH-2004R TRANSMISSION STAGE 2
  • 120-1200Includes: All upgrades of Stage 1 plus hardened Sun Shell, 3 Clutch 4th Gear Set Up, 6 Clutch 3rd Gear Direct Drum, and HD Rear Planet Bearing. Rated @ 400 HP/TQ
  • PART#GM TH-2004R TRANSMISSION STAGE 3
  • 120-1300Includes: All upgrades of Stage 1 & 2 plus Forward Drum with Welded 300M Billet Main Shaft, Wide 2nd Gear Carbon Band, and Super Hold 2nd Gear Servo. Rated @ 500 HP/TQ
  • PART#GM TH-2004R TRANSMISSION STAGE 4
  • 120-1400Includes: All upgrades listed above plus 300M Billet Input Shaft, Rollerized Center Support & Low Support, and Constant Pressure Valve Body. Rated @ 600 HP/TQ (N2O Kits OK)
  • PART#OPTIONAL PARTS
  • 120-7000TH-2004R Deep Aluminum Pan
    120-8000Trans Brake Valve Body
    120-9000Billet Overdrive Planetary
    120-9001Billet Output Shaft
    120-9002Billet Overdrive Ring Gear

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