GM 4L60E/65E/70E (Electronic) Transmission Superior Shift Correction Kit With Boost Valve This Shift Correction Kit from Superior will improve all 4L60E/65E/70E Transmissions from 1998-Up. 4L60E-Late Kit with valve Shift Correction Package This valve body kit deals with these problems:* Code 1870* Delayed engagements* Slide bump 2nd & 3rd* 3-4 clutch burn-up* Help for worn plates* Provides more lube oil* Regular and Heavy duty applications* Improves overall transmission performance Includes PWM Powervalve to correct code 1870 problems and still maintain normal computer strategy of the converter.2. Includes oversized checkballs to give new life to the original worn separator plate.3. New .474 boost valve included to replace worn OE valve. This Shift Correction Kit will come with installation directions in English and illustrations.