This valve body is available in stock shift pattern or altered shift pattern (PRNO/D21) which allows for greater manual control. You can hold 1st and 2nd gear. Overdrive gear will automatically lock out at wide open throttle. Choose from stages 1-3. Stage 3 is a hard tire chirping shift (recommended with high stall torque converters). Use stage 1 for stock converters with lock up. Use stage 2 for high performance street/strip with non lock up converters. Specify which stage you prefer and stock or altered shift pattern in the comments box at check out or place your order by phone. If you forget, we will call or email you and ask.