1970-72 Corvette ZR1
The ZR1 name first appeared without a hyphen during the 1970 model year, when it was a performance package for the C3 Corvette.
The third-generation Corvette ZR1 was first introduced in 1970 as the successor to the L88 Corvette. The car, which could be ordered as Regular Production Option (RPO) ZR1, came equipped with a new, solid-lifter, small-block engine that GM designated the LT1. The LT1 engine, which was manufactured by GM from 1970–1972, was a 350 cubic-inch small block that produced 370 horsepower. It featured 11:1 compression, a ‘178’ high-performance camshaft and a 780 CFM Holley four-barrel carburetor mounted to a special aluminum intake. Although not as powerful as the L88, the LT1 engine offered consumers an exciting engine platform that could power their Corvettes at and around the racetrack.
In addition to the LT1 engine, Corvettes ordered with RPO ZR1 came equipped with the M22 “Rockcrusher” transmission, heavy-duty power brakes with dual-pin front brake calipers (J56), a transistor ignition, a special aluminum radiator and a heavier-duty suspension package that included bolstered 7-leaf rear springs, shocks and heavy-duty 5/8 inch front sway bars and rear spindle struts/stabilizer bars. The car also came equipped with metal fan shrouds. Moreover, when ordering a ZR1, the following options were deleted from the Corvette, including: a rear window defroster (C50), air-conditioning (C60), power steering (N40), deluxe wheel covers (P02), the alarm system (UA6), AM/FM radio (U69) and AM/FM Radio, stereo (U79).
The deletion of these items was intentionally designed to help reduce the car’s overall weight as well as to reduce the power load put on the engine, thereby ensuring that more power was transferred from the engine, through the transmission and to the rear wheels. In fact, it was impossible to order the ZR1 with any of the “creature comforts” synonymous with the more conventional Corvettes being offered by Chevrolet dealers across the nation. Despite this, the 1970 Corvette ZR1 could be ordered as a convertible!