For raw sex appeal and top bragging rights at your local cruise night, nothing beats a vintage big-block Corvette. When it comes to sheer driving pleasure, however, Chevrolet’s most powerful small-block V-8s arguably take first prize. A 350-cubic-inch “SBC” (“small-block Chevy”) weighs about 120 pounds less than a comparably equipped 454, and there’s no denying the immutable laws of physics. Trimming more than 100 pounds from the front half of a 3,400-pound car enables it to accelerate quicker, stop sooner, and handle better. The small-block Corvette is also easier to service, less prone to overheating, and more abstemious with fuel.
The small-block’s potential to produce excellent power from a reliable, lightweight, and comparatively inexpensive package was evident from the moment it was introduced in 1955. In successive years displacement grew steadily from the original 265 cubic inches to 283 in 1957, then 327 in 1962, and finally 350 in 1969. (See our related story, elsewhere in this issue.)
Though the 350 SBC endured for many years beyond its introduction in 1969, and subsequently went into tens of millions of Chevrolets and other GM vehicles, many enthusiasts believe the engine peaked in 1970, at least in terms of raw power and torque. With increasingly strict emissions and fuel-efficiency regulations looming on the horizon, that year represented the final opportunity for Chevy to offer Corvette buyers a high-compression engine with an aggressive camshaft profile that was nearly race-ready right off the showroom floor—and that’s exactly what they did.
In 1970, when our feature car was built, a 300-horse 350 was standard equipment in the Corvette. That same year two optional versions of the 350 were offered for the performance-minded. Buyers who wanted more power without sacrificing the convenience of hydraulic lifters could get the 350-hp L46 for $158 more, and 4,910 of them did just that. For a stout $447.60 over the base price ($4,849 for a convertible and $5,192 for a coupe), dedicated enthusiasts could get the LT-1, which produced a healthy 370 horses. The steep price and added maintenance that went along with solid lifters help explain why only 1,287 buyers checked the box for the most potent small-block.
While the cost for an LT-1 was sobering, buyers certainly got their money’s worth. Four-bolt main bearing caps anchored a forged steel crankshaft, while the connecting rods and pistons were forged as well (from steel and aluminum, respectively). High domes on those pistons, in concert with large-valve cylinder heads, yielded a power-enhancing 11.0:1 compression ratio. An aggressive, solid-lifter cam channeled the air and fuel—mixed together by a 780-cfm Holley four-barrel carburetor and an aluminum intake manifold—into the combustion chambers.
The high-rise intake and open-element air cleaner needed additional clearance, so all LT-1 Corvettes got a special hood that was nearly identical to the 1968-72 big-block version. The bonnet’s shapely bulge was accented by twin paint stripes, and “LT-1” stickers on either side let the whole world know what lay beneath.
With so few LT-1 Corvettes made in 1970, good examples that still retain their original engine are somewhat scarce, making our feature car highly desirable. What makes it even more unusual are the mild period modifications it retains, and the more modern updates it has received. The latter were begun by Greg Lotko, the car’s prior owner, because he wanted to make it more fun to drive. Before the work was completed, however, Lotko traded the car to his friend Jeff Henry, the current owner.
“I loved the car,” Henry explains, “but Greg wasn’t really interested in selling it. He did mention that he wished it was green instead of silver, because he loves green. By sheer coincidence, I spotted a Donnybrooke Green 1970 LT-1 scheduled to go through an auction in Florida, and I had Dave Weber, from CMC Motors/Dream Car Restorations, fly down there to look at it. Dave confirmed that it was a really good car, with its original engine, so I bought it and traded that to Greg.”
Henry was on the same wavelength as his friend regarding the desire to make the car more fun to drive, so CMC Motors/Dream Car Restorations continued with their work after Henry became the Corvette’s steward. Up front they rebuilt the car’s suspension with new, OEM-spec springs, bushings, bearings, and ball joints. The original-style Delco shocks gave way to KYB gas units, while a Borgeson power-steering setup replaced the original Saginaw box. New tie-rod ends, an idler arm, and a 7/8-inch anti-sway bar completed the front-end restoration.
At the other end of the car, KYB gas shocks and a lightweight fiberglass leaf spring from Van Steel replaced the factory parts. CMC Motors/Dream Car Restorations also sourced a rear anti-sway bar setup and offset trailing arms from Van Steel. These custom arms have the same forward mount points, lower strut-rod anchors, axle-flange location, and spring-mount location as the original Chevy arms, but the offset between the forward mount and bearing hub provides extra clearance for bigger aftermarket wheels and tires.
Though the car’s rear wheels look like GM Rallyes, they’re actually wider than the original factory rims. Combined with commensurately fatter tires, they improve handling and braking performance while preserving a somewhat factory appearance. BFGoodrich Radial T/A tires measuring 255/60R-15 ride on 15×8-inch wheels up front, while 275/60R-15 Radial T/As hug 15×10-inchers in the rear. The stock steel trim rings were left off at all four corners because Henry likes the look better.
The chassis rehabilitation was completed with a total brake-system overhaul. The power brake booster was rebuilt, stainless steel–sleeved calipers were fitted all the way around, and new steel lines and hoses, along with a new master cylinder, were installed. Even the parking-brake setup got a complete refurb.
The original LT-1 engine still ran extremely well, so Weber and crew at CMC Motors/Dream Car Restorations recommended against a total rebuild. But to ensure reliability, they did replace the timing chain and oil pump. They also installed a new harmonic balancer because the rubber mating the two halves of the original balancer had deteriorated. Other than those parts, the only other engine work consisted of new gaskets, seals, hoses, and belts; a cooling-system flush; a new thermostat; and the requisite oil-and-filter change.
Again in the name of reliability, the team working on the car installed a new Ram clutch and pressure-plate assembly, and rebuilt the car’s original M21 close-ratio four-speed gearbox. They also rebuilt the original Positraction differential with new bearings, limited-slip clutch plates, and related parts. They reused the original 4.11:1 ring and pinion gears, which remained in virtually new condition, but did replace the unit’s side yokes with new heavy-duty ones. And while the transmission and rear end were out, they replaced the U-joints in the driveshaft and half-shafts to complete the restoration of the car’s drivetrain.
The exhaust system wasn’t in terrible shape, but Henry nevertheless had it replaced with a new stainless-steel system that included custom-made headers. All of the fabrication for that job was done at a Long Island shop called East Coast Headers.
Though the car’s paint is obviously quite old and has its fair share of blemishes, Henry decided to leave it alone, at least for now. “It has a soft patina that I like,” he explains, “and I can drive it all the time without worrying about getting a stone chip or a scratch here and there.” The restorers did, however, replace the door and T-top weather stripping, which were original and in relatively poor condition.
The interior was mostly original and also showed its age in various spots, so Henry decided to make some upgrades there. The car’s standard black interior was swapped out for the bits from the Custom Interior Trim package, a $158 option that went into 3,191 Corvettes in 1970. The extra-cost interior includes leather seat covers, nicer “cut pile” carpeting, wood-grain accents on the center console and upper door panels, and carpeted trim on the lower portions of the door panels. Before those bits were installed, however, Dynamat acoustic and thermal insulation was applied to the floor and doors.
All but 325 of the 17,316 Corvettes made in 1970 came with either a U69 AM-FM radio (a $172.75 option) or a U79 AM-FM stereo radio ($278.10). Both of the available radios sound awful by today’s standards, even when in proper working order, so Henry had the techs at CMC Motors/Dream Car Restorations install a RetroSound Motor 4 unit. While looking period correct for the car, this setup offers improved sound quality and modern conveniences, including Bluetooth connectivity. To get the most out of the modern stereo, new speakers were also installed.
The final area the restorers addressed was the car’s electrical system. They cleaned and secured every ground and harness connection point, and replaced any switches that looked questionable.
In the future, Henry will likely replace the original vacuum-operated wiper door and headlight mechanisms with off-the-shelf electric-motor conversions. Other than that, his only plans are to “drive the wheels off” the car.
“I’ve loved Corvettes ever since I was a child,” he tells us, “and this car really is something I dreamed of owning one day. It’s the best combination of an authentic, classic C3 with some modifications that make it an absolute blast to drive.”
