This is a new brake master cylinder for 1967-1970 Chevrolet & GMC trucks. The bore size is 1-1/8" diameter. Check against your original. Replaces GM# 3912128
1967-1970 Chevrolet & GMC 3/4 & 1 Ton Trucks (exc. D-D, 11,000# Axle) - Series 20 & 30;
1968-1970 Chevrolet & GMC 3/4 & 1 Ton Trucks (D-D), (exc. 11,000# Axle) - Series 20 & 30
This part fits most 1967 1968 1969 1970 Chevrolet Trucks; exceptions may apply. Please read the complete description to see if this part fits your specific vehicle and application.
This product can expose you to a chemical, which is known to the State of California to cause cancer or reproductive harm.
For more information go to www.P65Warnings.ca.gov