Why It Matters
A wide-ratio four-speed was standard; M21 and M40 Turbo Hydra-Matic were alternatives. Case, stamp or tag, date, ratio, shifter, linkage, drivetrain compatibility, and paperwork must agree.
Also Known As
1973 Corvette four-speed1973 Corvette M211973 Corvette Turbo Hydra-Matic