ZZPerformance gear ratio conversion kits are based on the single chain/gear setup used some GM transmissions. The stock 4t65e uses a weak double chain setup which can fail or wear out quickly on a modified car. By upgrading to our modified gear/single chain setup strength of the system can be increased by over 30%! This is a stronger setup than the 15/16" chain setup that is also available with some other vendors.
Kits include:

• Drive sprocket
• Driven sprocket
• Channel plate gaskets
• Valve body gaskets
• Thrust washer
• 7/8" drive chain

Stock gear ratios:
2.93 - 97+ Grand Prix GTP, Regal GS, Bonneville SSEi, 04+ Monte Carlo/Impala SS (3.29 diff & 37/33 tooth gears)

3.29 - 97-03 Grand Prix GT, 04+ GTP Comp G-only (3.29 diff & 35/35 tooth gears), 00-03 Monte Carlo/Impala SS 

3.05 - Most NA cars- 04+ Grand Prix GT (non supercharged), Regal/Lasabre, some NA Bonneville/Park Avenues, Monte/Impala (non SS) (3.05 diff & 35/35 tooth gears)

2.86 - some NA Bonneville/Park Avenues(2.86 diff & 35/35 tooth gears)

3.69 - Note: We currently are not carrying this option.