1970–72 Chevrolet Corvette LT1: A Goldilocks Value Proposition

Among second- and early third-generation Corvettes, big-block cars tend to dominate any debate about which spec of America’s sports car is king. There are some exceptions, though: The L84 “Fuelie” in the early cars is a favorite, though the small-block Chevy that’s perhaps in the best position to fight for the prize is the 350-cubic inch mill that came with the Regular Production Option (RPO) LT1.

LT1-equipped third-generation Corvettes delivered a balanced blend of power, higher-revving personality, and handling that contrasted with the brute force of the big-block cars. Today, they remain among the most sought-after C3 Corvettes, though their prices haven’t gone through the roof.

By 1970, the Mako Shark II-concept-inspired design of the third generation was in its third year, and Chevy decided to perform some subtle stylistic updates and improvements. The fender flares were widened to reduce rock chips, while the front end got an egg-crate grille and treatment to the side vents similar to those on Bill Mitchell’s Aero Coupe styling exercise from 1969. Side markers front and rear grew in size.

Inside, high-backed seats integrated the headrest, and the Corvette was now available with a “custom interior” option that offered better touch points all around—leather seats and shift boot, woodgrain dash, and improved carpeting. This may have been appreciated, but the real cause for conversation was what was available—and not available—beneath the Corvette’s forward-tilting hood.

Before getting too far, let’s take a brief pause for clarification of references. LT1 is, as mentioned above, an RPO code. The engine it came with is commonly—though not always—referred to as the LT-1 (dash included), not to be confused with the 5.7-liter LT1 (no dash) that powered Corvettes, F-bodies, and select full-size GM cars in the ’90s. You will see the RPO and the engine designation in this piece in their appropriate circumstances.

Coming from the L88 427-cubic inch big blocks of 1967-69, and with the 450-horse, 454-cubic inch LS6 headed for use in the Chevelle, there was a good deal of anticipation for a high-output 454 in the Corvette. Chevy did intend to provide one—RPO LS7 was rated at 460 horsepower, and though early ’70 Corvette brochures did include this beast, the engine was unfortunately never put in a Corvette that was sold to the public.

That left the 390-horse LS5 454 as the only big block option for that year. In offering a massive 500 lb-ft of torque, the LS5 confidently got the job done, but was neither a wind-it-out screamer nor the outright monster that the L88 had become known as.

All this created a lot of context for the new-for-1970 LT-1. When comparing the LT-1 to the LS5 and the 270-horse engine in the base Corvette, Car and Driver in-period characterized the differences bluntly: “But those powerplants are of little interest to the Corvette purist, the man who remembers the soul and vitality of the high-winding fuel-injected 283 when it was the only street engine in the country that put out one horsepower per cubic inch. Today’s equivalent is the LT1…” High praise indeed, and truly highlighting the LT-1’s position in the lineup.

At its core, the LT-1 represented a thorough hot-rodding of Chevy’s proven small-block formula. It’s often characterized as a more hardcore version of the potent hydraulic-lifter 350-horse L46 that debuted the prior year, and the two did share a number of parts, including the same block and cylinder heads, along with the same 11.0:1 compression ratio in 1970.

The LT-1 traded those hydraulic lifters for a set of solid ones that responded to a more aggressive cam. Lighter, TRW forged aluminum pistons with revised rings were added to help put up with more abuse, while stronger connecting rods and wrist pins along with a forged, balanced crankshaft rounded out changes to the rotating assembly. Four-bolt mains held the crank to the block, and improved rod and main bearings, a gear-driven oil pump and a different oil pan design helped ensure proper lubrication. Up top, 2.02-inch intake valves and 1.60-inch exhaust valves made for freer-breathing heads over the base 350, and a Winters aluminum high-rise manifold wearing an 800-cfm Holley carburetor voraciously mixed the fuel.

The result was 370 horsepower at 6000 rpm—the LT-1 would keep pulling to a then-heady 6500 rpm—and 380 lb.-ft. of torque at 4000. Peak power was up by 20 over the L46, and it was made a full 400 rpm higher in the power band. Torque figures were the same, though again there was a 400-rpm difference in the peak. Backed by a standard four-speed manual or a more assertively-geared Muncie M-22 “rock crusher” gearbox, and optional performance gear sets, Chevy had built an engine and drivetrain that wanted to go.

And go it did, on the straights, and through the corners. Those who have driven both big- and small-block examples note that the balance of the car is markedly more even, with the small block weighing as much as 300 pounds less than the 454-powered cars. Though the big block cars wore a rear anti-sway bar to help offset their nose-heavy manners, the lighter front end of the small block-powered cars was effective in improving steering feel and overall agility.

Whether it was as easy to live with every day was a different question. The LT-1’s ability to run at higher rpms coincided with a tendency in testing to throw air conditioning compressor belts, and as a result, AC wasn’t immediately available on the model. The L46 or even the LS5 may have been the more sound, if less dynamically pleasing, choices for drivers who wanted power in everyday driving scenarios, but it was the LT-1 that pulled at the enthusiast’s heartstrings. Of the 17,316 Corvettes that would sell in 1970, 1287 were LT1s.

1971 brought about more changes, two of which weren’t good for the LT1. The first and most notable was a drop in compression to 9.0:1. That two-point drop trimmed horsepower to 330—still a solid figure, but the wrong direction nonetheless. The second was the late arrival of the LS6. Though compression neutered it somewhat to 425 horses, down 25 from its rating in the 1970 Chevelle, the LS6 still had plenty of character. “It’s like the LT1 only bigger,” beamed Car and Driver. That was a boon for the go-fast crowd, but maybe not for the future of the LT-1. The availability of a raw, rowdy LS6 with nearly 100 more horsepower, along with the LS5, which was more relaxed but still faster than the LT-1, begged the question: Did buyers really want a high-strung small block, too?

The answer to that question was mixed. Sales did improve for 1971, with 1949 buyers choosing the LT1. (It should be noted that 1970 was a short model year, with cars debuting in February, so sales figures between years aren’t truly apples to apples.) The LS5, though, sold significantly more, at 5097. Also, the L46 was no longer available, likely steering buyers who wanted more livable power over the base car to the LS5.

Those who know this era well can easily recite what’s coming next. 1972, the final year for the LT-1, GM switched its horsepower rating from gross to net, and power “went down” to 255 hp. The good news was that this was a paper number—the engine remained essentially unchanged from 1971. On the upside, Chevy figured out how to keep the AC belt from flying off the engine, so cool interior air was available as an option in ’72. Even though the power wasn’t the same as the LT-1 that wowed small-block fans in ’70, it maintained the personality that it debuted with, and a 4.11 gear swap did wonders to help wake up the performance of the later cars. That said, sales dipped to 1741 LT1s out of more than 27,000 total Corvettes.

Come 1973, the LT1 disappeared from the order form, leaving the base 200-horse L48 350, the 250-horsepower L82, and the lumbering 275-horse LS4 454 to carry on. The days of the screaming small block were done, at least for the moment.

It’s worth rewinding the tape a bit and highlighting an even more performance-oriented Corvette where the LT-1 engine found a home. Chevy had an inkling that buyers ordering a high-strung small block were a different breed, many of whom were seeking more of a sports car feel from their Corvette. So, to complement the LT-1’s personality, RPO ZR1 helped transform the rest of the car.

Possessing the LT-1 engine but going by its ZR1 RPO code, these first Corvettes to bear the ZR1 designation made the M-22 transmission standard, added an aluminum radiator, heavier-duty springs, shocks and sway bars, more powerful brakes, and a different fan shroud. Several options were unavailable on the ZR1, including air conditioning, a defroster, radio, and power steering. This truly was the hardcore option, and as you might expect, sales reflected that. Just 25 ZR1s were sold in ’70, eight in ’71, and another 20 made it out the door in 1972. It stands as the most potent and capable small-block C3 Corvette package, and among the most collectible as well.

“Looking back, the LT1 is one of the most admired Corvettes and ‘Vette engines in history,” says Don Sherman, a marque expert and regular Hagerty contributor. “There were two camps: Big block and small block. But the character built into the LT-1 would be very important for future Corvettes, and the LT-1 remains much loved to this very day for its performance and its historical impact.”

This reverence is generally reflected in the LT1’s values: Setting aside the ultra-rare ZR1, RPO LT1 commands a solid premium over the other third-gen small block-equipped Corvettes. And, among 1970 Corvettes, the LT1 is the most valuable, regardless of displacement—a #2 (excellent) condition LS5 454 is $9000 cheaper while the tamer L46 comes in 12 grand beneath the LT1. Naturally, the most potent 1970 LT1s are also the most valuable, but it’s also worth noting that solid driver-quality examples can be had for less than $40,000.

The slight premium the LT1 carries over those other ‘Vettes pales in comparison, though, to the value delta between the top-flight big blocks and the rest. Number 2 condition values for L88 cars from ’68 and ’69 come in north of $400,000, and a same-condition 1971 LS6 is valued $188,000, more than double a ’70 LT1. In that light, the LT1 delivers quite a bit of attitude per dollar.

Perhaps surprisingly, given its place in Corvette history, the LT1’s allure does not appear to have been picked up on by younger generations of enthusiasts. Boomers make up the overwhelming majority of quotes sought for LT1 Corvettes at 62 percent. Gen X and younger generations each make up shares markedly less than their overall market stakes. That said, we don’t think the LT1 will be forgotten anytime soon—rather, it may continue to represent a solid entry point to a high-performance, third-generation Corvette experience.

Its three-year lifespan may have been fleeting, but the LT1 effectively put a capstone on early small-block performance in the Corvette and served as an inspiration as the model returned to a powerful era again in the ’90s. For modern enthusiasts who are looking for the right mix of history and capability at a non-stratospheric price, the LT1 makes perfect sense.

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