Chevelle SS (Second generation)

A Fresh Shell and a Series of Its Own Chevrolet redrew the A-body for 1968 around two wheelbases: 112 inches for two-door coupes, convertibles and the El Camino, 116 inches for four-door sedans and wagons. The result was a long-bonnet, short-deck shape with a semi-fastback hardtop roof, and the SS 396 was a separate series that year rather than an option: 60,499 sport coupes, 2,286 convertibles and 5,190 El Caminos. Standard equipment was plainer than the badge suggests: a bench seat, an open differential and a three-speed manual, with buckets, gauges and a four-speed all extra. Three 396 cu in Mark IV engines were offered, the L35 at 325 bhp, the L34 at 350 and the solid-lifter L78 at 375.

The Option Code Years For 1969 the SS 396 series was abolished and the same equipment returned as RPO Z25, taken by around 86,307 cars. That is the change which makes everything afterwards difficult: from this point the car is a package rather than a model, and the VIN stops recording it. For 1970 General Motors lifted its self-imposed 400 cu in ceiling on intermediate cars and Chevrolet used the room at once. The 396 was bored to 402 cu in but kept its badge; Z25 remained the SS 396 at $445.55, with the L34 350 bhp engine standard and the L78 375 bhp version available until 30 October 1969. Alongside it came RPO Z15, the SS 454, at $503.45.

Four Hundred and Fifty Gross Z15's standard engine was the LS5, a hydraulic-lifter 454 rated at 360 bhp at 4,400 rpm and 500 lb-ft at 3,200. For roughly $263 more the LS6 replaced it: 11.25:1 compression, forged crankshaft, rods and pistons, solid lifters, an aluminium intake and a Holley four-barrel, rated at 450 bhp at 5,600 rpm with the same 500 lb-ft at 3,600. That was a gross figure, taken on a stand without air cleaner, exhaust system, alternator or fan. Gearing was 3.31:1 with the automatic or 3.55:1 with the four-speed, with 4.10:1 available. The car around the engine was less accomplished: Car Life's January 1970 test of a 350 bhp SS 396 recorded 15.5 seconds at 90.42 mph from a 3,990 lb kerb weight carrying 58 per cent over the front axle, with heavy understeer and brakes that faded.

Two Numbers for the Same Engine 1971 changed the arithmetic more than it changed the cars. General Motors required its engines to run on low-lead or unleaded fuel, compression fell to 8.5:1 or below, and Chevrolet began publishing SAE net figures, measured with the engine's own accessories and exhaust fitted, alongside the traditional gross ratings. The LS5 was quoted at 365 bhp gross and 285 bhp net; the 402 read 300 gross and 260 net. Neither pairing describes a like-for-like decline, and reading the 1971 figures straight against the 1970 ones without noting the method is the most common error made about these cars. Z15 itself became an equipment package orderable with any of the four optional V8s, which is why a genuine 1971 SS can carry a 350.

The Badge Outlives the Engine For 1972 gross ratings were dropped entirely. The 454 LS5 read 270 bhp SAE net, the 402 read 240 and the two 350s 165 and 175. Z15 remained available on the Malibu sport coupe, convertible and El Camino, and 24,946 cars took it, more than in 1971. The lasting benefit to later owners was an engine letter in the VIN, W denoting the 454, which could only be ordered with the package. It was the final year for cowl induction on the 454, and the final year of the second-generation shell.

Mechanically these are simple, over-built cars and the drivetrains have no signature failure. A long-standing Chevelle specialist quoted by Hagerty could think of nothing genuinely wrong with any of them beyond the fact that period gasket technology means they all leak oil. The structure is where the money goes. The perimeter frame and its body mounts corrode from the inside, and the panels rust in a consistent order: the base of the rear window first, which then drains into the boot and rots the parcel shelf and boot floor; the quarter panels behind the rear wheels; the lower corners of the doors; the bottoms of the front wings; and the floor pans, particularly under the windscreen. Cars fitted with a vinyl roof trap moisture beneath it and bubble along the rear pillars, and convertibles rot in the inner rockers, which is structural on an open car. Replacing the rear glass on a hardtop requires the quarter panel to come off, so a leaking rear screen is rarely a cheap repair. Big-block cars add mass to a nose that already carried 58 per cent of the weight, and worn front bushings, sagging springs and tired steering boxes are normal. Reproduction sheet metal is abundant, but fit quality varies and imported panels frequently need reworking.

Identification comes before condition on this car. In 1968 the SS 396 was its own series and the VIN says so. From 1969 to 1971 it was an option code and no part of the VIN records it, so a car of those years cannot be authenticated from the metal alone. That is why the paper trail - build sheet, Protect-O-Plate, dealer invoice, warranty card, window sticker - carries so much of the value. The exception is 1972, when Chevrolet placed an engine letter in the VIN and the 454 code W could only be ordered alongside Z15. Cars assembled at Oshawa, Ontario carry their RPO codes on the Fisher body tag; a US-built 1970 trim tag carries no such record. Expect claims to outrun evidence, since Chevelle club officials report that cloned paperwork now circulates alongside cloned cars. On an LS6, treat the stamped partial VIN on the engine pad and the casting and assembly dates as a starting point rather than a conclusion, and ask what independent record supports any body-style rarity claimed, since the LS6 Registry publishes calculations and says so. Beyond the paperwork, check the frame and its body mounts before the panels, lift the boot mat, and look along the base of the rear screen.

As of August 2026, classic.com's benchmark for the second-generation Chevelle SS stands at $87,120 on a rising trend, with an average recorded sale of $100,381 and 72 cars listed for sale. The tracked range runs from an anomalous $1 entry recorded against a 1970 SS 454 LS5 M22 on 24 March 2026 to $209,900 for a 1970 SS 454 LS6 on 30 June 2026. Auction evidence sits well above the benchmark at the documented end. Mecum sold a numbers-matching LS6 M22 convertible, chassis 136670B188926, for $770,000 including buyer's premium as lot S187 at Kissimmee on 17 January 2026 - the highest price paid for any Chevelle at public sale, ahead of the $600,000 record set in May 2024. A documented LS6 four-speed made $192,500 at Barrett-Jackson Palm Beach in April 2025, against reported sales near $87,000 for an example whose broadcast sheet could not be produced on the day. Hagerty's market writing places a four-speed roughly 15 per cent ahead of an otherwise equivalent automatic, and notes that big-block Chevelles, LS6 cars first, recovered their pre-2008 values faster than the rest of the field.