Real 1970 Chevelle SS 454 or Clone? How to Tell

Why SS 454 Clones Are So Common

For 1970 the Super Sport was an option package, not its own model. Chevrolet sold two of them: Z25, the SS 396, and Z15, the SS 454. Z15 came with either the 360 hp LS5 or the 450 hp LS6 big-block, and production records cited by enthusiast references count 8,773 Z15 cars, 4,475 of them with the LS6 and 4,298 with the LS5.

The rest of the Chevelle line used the same bodies. Stripes, badges, cowl induction hoods and SS dash parts are all reproduced, and a 454 can be dropped into a Malibu that left the factory with a six or a small-block. Many of these cars are sold openly as tributes or clones. The trouble starts when one is sold as the real thing, sometimes by an owner who has never known otherwise.

What the 1970 VIN Can and Cannot Tell You

The 1970 Chevelle VIN has 13 characters: 1 for Chevrolet, two digits for the series, two for the body style, 0 for 1970, a letter for the assembly plant, then a six-digit sequence number. A V8 Malibu sport coupe starts 13637, and a Malibu convertible uses body code 67.

What the VIN does not have is an engine code. Nothing in a 1970 VIN says 396, 454, LS5 or LS6, and nothing says SS. A real SS 454 coupe and a Malibu with a 307 can carry the same 13637 prefix. A listing that claims the VIN proves a 454 is wrong.

The 138 series causes confusion. From 1966 to 1968 the SS 396 was its own series, and a VIN starting 138 identified one. From 1969 the SS became an option, and the 138 series was left to wagons and, in 1970, the Monte Carlo. So a 1970 Chevelle coupe or convertible sold as an SS should start with 136, and a 136 VIN proves only that it was a V8 Malibu. The 1970 rule is simple: the VIN can rule a car out, but it cannot rule one in.

The Cowl Tag and Its Limits

The Fisher Body number plate, usually called the cowl tag or trim tag, carries the model year and style number, the assembly plant, a body number, the interior trim code, the paint code and a build date written as a month and a week letter. Check that the year, plant and style agree with the VIN, and that the build date fits the rest of the car.

It will not settle the SS question. Fisher Body did not record the engine on most 1970 tags, and the SS option is documented mainly on tags from the Oshawa, Canada plant, which listed RPO codes. A tag can show a car is a 1970 Malibu coupe from the right plant, nothing more. Some plants also stamped data processing numbers that experts compare against the build sheet.

Engine Stamp and Suffix Codes

A 1970 big-block carries an engine code on the front pad: a plant letter, a four-digit month and day, and a three-letter suffix showing the size, the horsepower and usually the transmission it was built for. Published Chevelle tables list these 454 suffixes:

- CRQ: LS5 with Turbo Hydra-Matic 400
- CRT: LS5 with M22 four-speed
- CRR: LS6 with Turbo Hydra-Matic 400
- CRV: LS6 with M22 four-speed

Other codes for heavy-duty clutches (CRU, CRX) and a disputed aluminum-head LS6 also appear, and CRN is generally listed for the Monte Carlo LS5, though sources differ on it. Z15 required either the M22 or the heavy-duty TH400, so a suffix should agree with the gearbox in the car.

The block should also carry a partial VIN, typically the year digit, the plant letter and the six-digit sequence number, which must match the car. Its position varies by plant, and on rough casting it can be faint. Check the block casting number and date code too, and look for signs that the pad was ground or decked. A correct suffix on a block of the right era proves only that the engine is a 1970 454, not that it is the engine this car was built with.

Build Sheet, Protect-O-Plate and Other Clues

Because the VIN and cowl tag stay quiet, original paperwork does the real work. A build sheet lists the RPO codes the car was built with, including Z15 and the engine. The Protect-O-Plate, the metal warranty card given to the first owner, carries the engine code. A window sticker or dealer invoice helps as well. Original documents matter most, since reproductions exist.

The car itself gives clues. In one documented case, a 1970 SS 454 LS6 convertible had been owned for more than 35 years before a specialist found it was likely a small-block Malibu from the factory. The giveaways included a wrong font on the engine VIN stamp, unboxed lower trailing arms, missing firewall provisions and the wrong hood. Registries such as the LS6 Registry and owners' groups like the National Chevelle Owners Association are places to start, and a paid inspection by a recognized Chevelle expert is worth it on any car priced as a real SS.

Why It Matters for Value

The price gap is what drives clones. Citing Hagerty's valuation tools, Motorious put a 1970 Malibu sport coupe with the base 350 V8 at about $14,300 in #3 (Good) condition and a genuine SS 396 sport coupe at about $70,500, with SS 454 cars reaching well into six figures depending on options and engine. Auction records also list Chevelles sold as SS clones at a fraction of that.

None of this makes a tribute a bad car. A clone sold as a clone can be a lot of fun for far less money. The problem is paying documented SS 454 money for a car that cannot prove it, so let the paperwork and the stamps set the price, not the stripes.