The 700-R4 is the four-speed automatic that defined the third-gen F-body's V8 driveline. Three-element torque converter, lock-up clutch in third and fourth, deep first-gear reduction (3.06:1) for off-the-line acceleration, 0.70:1 overdrive for highway cruising. Renamed 4L60 from 1990 model year as part of GM's 4Lxx transmission naming convention.
Heavy-duty version (RPO ML9) shipped behind the L98 5.7 to handle the higher torque load. Both share the same case and hardware; the ML9 has a different valve-body shift schedule.