1970's Golden Chevy Era - Rare V-8 Performance History Part 5

1970-1972: The End Of The World As We Knew It.

Doug Marion Oct 1, 2008 0 Comment(s)
Sucp_0810_07_z Rare_v8_performance_history 396_big_block 2/11

A hot 396 (402) big-block that needs to go down in history as a high rpm monster is the RPO L78 with 375 hp. And 1970 was the end of its production run (Chevelle).

The 1971 RPO LS3 (300hp 402) Chevelle sales were 17,656 and LS3 Camaros numbered a scant 1,533. The RPO LS5 (365hp 454) Chevelles were 9,502, full size cars were 6,831 and Corvettes were 5,097. Really rare was the RPO LS6 454 in the Corvette. Try 188. Chevy finally built ZR-2 Vettes-an even dozen (all LS6 powered). Corvette LT-1 350 sales were low at 1,949, eight of which were ZR-1s. The L48 (270hp 350) Nova sales were 7,016. Camaros were 6,843. Chevelles were a whopping 78,771.

Not many changes in 1972, but engines were now all rated in net horsepower terms instead of gross. This made them seem a lot lower than they were. Total Chevelle V-8 sport coupe sales went up 22,138 to 242,095. Chevelle convertible sales dropped 236 to 4,853. El Camino V-8 sales went up almost 14,300 to 57,147.

Sucp_0810_08_z Rare_v8_performance_history Yenko_deuce_nova 3/11

One of the best-launched new cars was the '68-'72 Chevy II / Nova. Add a potent L78, 375hp 396, axe the restrictive exhaust system, and you had a super car. This is why the COPO Novas were so popular. Ditto on the '70 LT-1 350 Yenko Deuce Nova.

Monte Carlo sales climbed 52,219 over 1971 to 180,819. Total Chevelle V-8 sales went up 117,265 to 605,289. Chevelle and El Camino L48 350 sales were 125,708 (up 46,937). Chevelle and El Camino SS 454 LS5 sales dropped to 5,333, but Chevelle SS cars jumped to 24,946 from 19,293 the year before.

The SS 454 option for the Monte Carlo was dropped after 1971, but you could still get a 402 big-block. Corvette sport coupe sales totaled 20,496, while convertibles were a mere 6,508. Total Chevelle Nomad V-8 wagon sales were 7,768. The RPO LS3 402 was ordered in only 970 Camaros and 20,031 Chevelles, El Caminos and Monte Carlos.

This was the last year the big-block Camaro was available in all states-except California-where it was not certified. Only 970 were sold, despite the bargain-basement price of $96 for the RPO. The RPO LS5 454 was in 3,913 Corvettes (also not certified in California). It was also in 5,333 Chevelles and 8,034 full-size cars. The RPO LT-1 350 was ordered in 1,741 Corvettes. The RPO L48 350 was in 5,584 Camaros.

Sucp_0810_09_z Rare_v8_performance_history Chevelle_vs_corvette 4/11

What's the difference between a 360hp 454 Chevelle and a 390hp 454 Corvette? Nothing, except the exhaust system and, of course, the horsepower rating.

The rarest Chevy go-fast RPO package in 1972 was the Corvette ZR-1. It cost a hefty $1,010.15 extra. Only 20 were so ordered. All of them were LT-1 350-powered.

And then it was over. For the next decade or so, performance from Chevy and Detroit pretty much took a nap. Even the fabled Z28 died after '74-Chevrolet's people supposedly would rather it be dead than to desecrate the name. The emphasis shifted from all-out performance to luxury as the offerings got bigger, heavier, slower and more option-laden. In the mid-'70s, two-door personal luxury cars like the Monte Carlo, Grand Prix and Cutlass exploded in popularity and, except for the Corvette, performance car sales died. It wouldn't be until around 1984 that Chevy would awaken from its slumber and start putting horsepower back into its automobiles.

Sucp_0810_10_z Rare_v8_performance_history Higher_ratio 5/11

To be efficient, Chevy V-8 engines generally need a compression ratio of 9.5:1 or higher. We've had a number of 8.5:1 compression engines-stock and modified-and they were pathetic performers. We once changed camshaft, intake, carburetor, headers and ignition in a Q-jet 454 like this one. Result: The mileage almost doubled (from 8 stock to 14-15 modified) and the Chevelle ran mid-high 14s using low and Second gear in the TH400.


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