Sonnax 350-LB1 Line Pressure Booster Kit for TH350 Transmissions

The Sonnax 350-LB1 Line Pressure Booster Kit delivers crisp, clean shifts without harshness for GM TH350 and TH350C automatic transmissions. This complete kit includes a large ratio boost valve assembly and a stronger pressure regulator spring that work together to provide progressive pressure increases as driving conditions become more demanding.

Key Features:

• Pressure regulator spring is approximately 10% stronger than OE and more conservative than other aftermarket springs
• Large ratio boost valve provides higher pressure incrementally when needed most
• Achieves modest pressure increase at low end with high-end pressure equal to or greater than other aftermarket kits
• Delivers normal engagements, smooth light throttle shifts, and coastdown shifts at low pressures
• Simple drop-in solution requiring no special tools or reaming

Performance Benefits:

• Shorter shifts and increased torque capacity without low-speed harshness
• Improved band and clutch holding capacity for increased durability
• Progressive pressure increase as driving conditions become more demanding
• All benefits of increased line pressure without overloading the pump at idle

Sonnax booster kit components are uniquely designed for precision pressure control, making this an ideal performance upgrade for stock, heavy-duty, and modified TH350 transmissions.