Street Lethal™ Automatic Transmission Assembly (20210-500) by J.W. Performance®.   Horse Power Rating: 450. This product is made of high-quality materials to serve you for years to come. Designed using state-of-the-art technology and with customers in mind. It will meet your needs and deliver great quality at an affordable cost. 

  • TH350 Street/Strip Transmission - Chevrolet OEM Case
  • Manual / Automatic Valve Body, performance shift
  • Standard 6" Tailhousing (other options available)
  • Requires minimum 14 in/Hg true manifold vacuum at all times
  • Performance Clutches and Steels
  • HD Intermediate Sprag Assembly
  • Fully Dyno Tested

Designed to deliver trouble-free, consistent performance
Right for your vehicle and lifestyle
Made from high-quality materials for ultimate durability
Manufactured to meet or exceed strict quality requirements


J.W. Performance Transmission, Inc. is a leading manufacturer of high performance automatic transmissions and components for drag and off road racers, street and strip enthusiasts, and more. Headquartered in Rockledge, Florida, J.W. Performance® manufactures thousands of quality transmissions and related parts ranging from flexplates to bellhousings. The company pioneered over 250 products since 1976. Many of its innovative solutions remain the industry standard and are widely used by professional racers in the United States and abroad. 

Street Lethal™ Automatic Transmission Assembly (20210-500) by J.W. Performance®.   Horse Power Rating: 450. This product is made of high-quality materials to serve you for years to come. Designed using state-of-the-art technology and with customers in mind. It will meet your needs and deliver great quality at an affordable cost. 

  • TH350 Street/Strip Transmission - Chevrolet OEM Case
  • Manual / Automatic Valve Body, performance shift
  • Standard 6" Tailhousing (other options available)
  • Requires minimum 14 in/Hg true manifold vacuum at all times
  • Performance Clutches and Steels
  • HD Intermediate Sprag Assembly
  • Fully Dyno Tested

Designed to deliver trouble-free, consistent performance
Right for your vehicle and lifestyle
Made from high-quality materials for ultimate durability
Manufactured to meet or exceed strict quality requirements


J.W. Performance Transmission, Inc. is a leading manufacturer of high performance automatic transmissions and components for drag and off road racers, street and strip enthusiasts, and more. Headquartered in Rockledge, Florida, J.W. Performance® manufactures thousands of quality transmissions and related parts ranging from flexplates to bellhousings. The company pioneered over 250 products since 1976. Many of its innovative solutions remain the industry standard and are widely used by professional racers in the United States and abroad.