Recent investigation of poor release of clutch, high pedal effort and disc wear has isolated the condition to the clutch fork retainer tangs interfering with the clutch housing boss provided for the ball stud which causes a reduction in fork travel.
The above condition is caused by a short ball stud Part No. 3887159 which was used on 1966 327 CID Corvette engines until 4-4-66. At that time the past design ball stud part No. 3729000 was again installed and is currently being used.
In the event a complaint of high pedal effort or poor release is encountered the unit should be inspected for the above mentioned condition. (see attached illustration).
The correct ball stud Part No. 372900 has an overall length of 1 12 inches, the shorter stud, Part No. 3887159 is approximately 1 3/8 inches long.
Your Reliability Data Center
Flint V-8 Engine Plant
Article ID: 1100
Created: January 12, 2015
Last Updated: January 12, 2015
Online URL: https://www.corvetteactioncenter.com/tech/knowledgebase/article/1966-corvette-reliability-data-center-letter-poor-release-and-high-pedal-effort-1966-327-cid-corvette-engines-1100.html