1991 Chevrolet Corvette Dealer Service Manual. Original.

This publication contains preliminary service information for 1991 Corvette, prepared before all of the final production specifications were established. Complete service information will be contained in a final service manual to be released later in the model year. This manual was to be discarded when the final version came out.
With the exception of anti-lock brake service procedures (Section 5E) and diagnosis (Section 5E1), refer to the 1990 Corvette Service Manual (ST-264-90) for brake service procedures.
With the exception of the shift control cable service procedures (Section 7A), refer to the 1990 Corvette Service Manual (ST-364-90) for automatic transmission on-vehicle service (Section 7A), diagnosis (Section 4L60 Diagnosis) and unit repair (Section 4L60 Unit Repair).
The above service procedures were either identical or were such that they did not require detailed service instructions at the time.