The 1969 ZL-1 Corvette, quite simply at the top of the pantheon of muscle cars back in the day.
The ZL-1 motor was conceived by Chevrolet as a lighter weight alternative to the legendary L-88. The L-88 was in itself, a beast of a motor with aluminum, open chamber heads, a 12.5:1 compression ratio, 2.19 intake/1.88 exhaust valves. Chevrolet added the now famous cowl induction L-88 hoodscoop to the 1968 Corvettes for better cold air/ram air effect. In fact, Chevrolet was the first manufacturer to draw cold air in from the base of the windshield where there was a low pressure area, rather than the forward facing hoodscoops of other classic muscle cars.
As Chevrolet power began to dominate Can Am racing, Chevrolet looked for a lighter version of the L-88 motor. They cast the block out of aluminum, rather than iron, which was revolutionary for the time in production cars. They added thicker main bearing webs, thicker cylinder walls and 4 bolt mains with a forged crankshaft, forged steel rods, forged pistons and a provision for dry sump lubrication. The camshaft was a 620 degrees lift/273 degrees duration solid lifter design. Anyone familiar with these lift and duration specs knows how lopey the cam is. The intake manifold was a high riser with dual planes, topped off by a Holley 850 cfm carb with mechanical secondaries.
The motor made its debut in the might Chaparrals of Jim Hall and the McLaren's of Bruce Mclaren. Hall used the ZL-1, both in the 2G and the 2F variants in 1967, while McLaren used in the M8A in 1968.
Zora Arkus Duntov, the godfather of Corvettes, decided to put one in a Corvette in 1969. The Corvette chassis was beefed up with J56 brakes, F41 suspension, J50 power brakes and a K66 transistorized ignition. The transmission was the famous M-22 Muncie "rock crusher", which I had in my 1969 Corvette. That was one stout, strong tranny. There was a G81 positraction rear end. Kustom headers designed special 4 into 1 collectors that swept out to the side of the car with long collector tubes extending back to the rear wheel well area. I had these same headers on my 1969 427 Corvette. While the car sounded mean and nasty, they left terrible burn marks on your leg if you were wearing shorts and were clumsy getting out of the car. Amazingly, Chevrolet listed the car as RPO-Regular Production Option, meaning that is was conceivable, someone could order it right from the factory.
The ZL-1 option was $3,010 in addition to the $1,032.15 L88 race option. Thus, a ZL-1 Corvette would have gone for $9,000, a princely sum back then. [As a footnote, I bought my first Corvette, a 427 tri-power roadster, in 1973 for $2,300.] Only 2 of these beasts were produced. Today, their collector's value is priceless.
Chevrolet decided to allow the car magazines to test Duntov's toy. Equipped with 4.88 gears, a Turbo400 automatic transmission, open headers and 10" drag slicks, which by today's standards, would be like driving on banana peels. [Remember, the rubber compounding and tire construction back then was bias ply and nothing like we have today.] MotorTrend tested the car and got a 10.89 @ 130 mph time. With stock gearing, the car's top speed was close to 200 mph. Quite simply, it was in a league of its own, trumping the mighty Hemi 'Cuda and Boss 429, two legendary King of the Hill musclecars.
I think I will periodically start threads like this to educate some of the younger people here on the forum about cars of yore.