Pages from the Past: Boss Hoss – the Street HEMI® Arrives

Muscle car historians face many conflicting and confusing artifacts on their way toward a fuller understanding of the cars and engines of the first muscle car era (1955-1972). In the case of this 1966 ad for the new HEMI® engine-powered Dodge Charger, the use of the tagline “Boss Hoss” has fooled more than a few new arrivals to the muscle car realm into making a false connection with Ford’s Boss 302 and Boss 429 Mustangs.

Classic ad

While Ford indeed used the term “Boss” to partially identify its canted valve 302 SCCA candidate (Boss 302) and “twisted HEMI” 429 NASCAR homologation bid (Boss 429) Mustangs, those painted ponies appeared three model years later, in 1969. And while there is no valid connection between a 1966 HEMI engine-powered Charger and a Boss Mustang other than the fact they’re all very fun, very fast four-wheeled personal conveyances, the fact remains that the 426 HEMI engine – like the special edition 302 and 429 discussed – materialized to satisfy something called “homologation”.

Having nothing to do with the dairy industry or cow’s milk, the term homologation refers to the act of manufacturing a sufficient quantity of some vehicle or engine (or combination of the two) in order to satisfy the sanctioning body of a specific type of automobile racing (think NHRA, SCCA, NASCAR, etc.) that said engine, vehicle or combination is indeed a regular production offering, available to John Q. Public through regular channels.

In the case of the 1966 Street HEMI engine-powered vehicle, it was NASCAR that forced Chrysler Corporation into mass production of this 425-horsepower, dual-carbureted, solid-cam-equipped beast. After the 1964 Daytona 500 grand slam – where Richard Petty’s 426 Race HEMI engine-powered number 43 1964 Plymouth Belvedere hardtop led a 1-2-3 HEMI engine-powered sweep of the first three winning spots – NASCAR asked Chrysler Corporation: “How ‘stock’ is that stock car you’re racing on our tracks”?

Well … although around 271 426 HEMI engine-powered vehicles had been installed in various Dodges and Plymouths in 1964, they were of a strictly limited availability configuration. You couldn’t just walk into a Mopar® dealership and buy a HEMI engine-powered car on a whim. Chrysler Corporation saw the Race HEMI as a special tool built for the special job of competing in sanctioned NHRA drag racing and NASCAR stock car racing events. By winning on Sunday with these highly specialized vehicles, they’d sell lots of less exotic 318 and 383 powered cars on Monday. Or that was the plan.

NASCAR – spurred by a very disgruntled and upstaged Ford Motor Company – called a halt to the proceedings. Though they didn’t disqualify the 1964 Race HEMI engine powered- vehicle’s accomplishments, for the 1965 race season, they told Chrysler Corporation, “Don’t come back with that thing until it’s available to anyone that wants one. Then we’ll consider it ‘stock’ and allow it on our race tracks.”

Chrysler (mostly) sat out the 1965 NASCAR race season but got very busy in NHRA drag strip competition with a fleet of 426 Race HEMI engine-powered A990 Dodge and Plymouth lightweight drag strip stormers and even some altered wheelbase rule benders for Factory Experimental. But NASCAR wasn’t forgotten…

Indeed, during the 1965 calendar year, Chrysler engineers came up with an answer to NASCAR’s homologation requirement. By de-tuning the Race HEMI engine-powered vehicle with lower compression, cast iron exhaust manifolds, a milder solid lifter camshaft and tandem Carter AFB carburetors, but keeping the inherent strength of the cross-bolted cylinder block and high-quality forged rotating assembly, the Street HEMI engine-powered vehicle was born. Though several 1965 Dodge and Plymouth test mules were seen running around the Chrysler Chelsea, Michigan, proving grounds (and Detroit’s Woodward Avenue), full-scale 426 Street HEMI engine-powered vehicle production commenced for the 1966 model year and this Boss Hoss magazine ad was part of the media blitz engineered to spread the word Chrysler Corporation was ready to race. On the NHRA drag strip, on the street and in NASCAR.

The campaign worked. Despite a steep $900 price tag (which included fortifications to the host vehicle consisting of an oil pan skid plate, leaf spring mount reinforcements, a pinion bumper plate, larger 3/8-inch fuel lines, police suspension and brakes, special emblems and a massive Dana 60 rear axle on four-speed cars), a total of 2,729 buyers drove off in their Street HEMI engine-powered Belvederes, Satellites, Coronets and, yes, Chargers in 1966.

NASCAR had no choice other than to allow Chrysler Corporation back onto its tracks and a pattern of domination resulted that ran right through the end of 426 Street HEMI engine-powered vehicle production in 1971. We like to think this “Boss Hoss” magazine ad played a big role in spurring the sale of 1966 HEMI engine-powered Chargers. And it did. Of the 2,729 Street HEMI engine-powered vehicles built in 1966, 468 were sleek, fastback-equipped Chargers. But the largest number of Street HEMI engine-powered vehicles – 817 – were installed in less expensive Plymouth Satellite hardtops.

Other 1966 B-body HEMI installation rates are as follows: 531 in Plymouth Belvedere II hardtops, 340 in Dodge Coronet 500 hardtops, 288 in Dodge Coronet 440 hardtops, 136 in Plymouth Belvedere I sedans, 49 in Dodge Coronet Deluxe sedans, 34 in Dodge Coronet sedans, 27 in Plymouth Satellite convertibles, 21 in Dodge Coronet 500 convertibles, 10 in Plymouth Belvedere II convertibles, 6 in Dodge Coronet 440 convertibles and 2 in Dodge Coronet four-door sedans.

In subsequent model years, the 426 Street HEMI engine continued its march to victory on the road and track (the new 1967 Dodge R/T muscle car nameplate reinforcing this “road and track” theme) but Street HEMI engine-powered vehicle sales volume never again broke the 2,000-unit mark. In descending order, 2,391 were built in 1968, 1,702 were built in 1969, 1,534 in 1970, 1,234 were built in 1967 and just 356 were built in 1971, the Street HEMI engine’s final year as economic and environmental issues snubbed demand.

As legendary as the Street HEMI engine-powered vehicle was and continues to be, we have to marvel at the fact today’s “third generation” 5.7L, 6.1L, 6.4L and 6.2L SRT® Hellcat/Demon/Redeye HEMI engine-powered vehicles have been produced in vastly superior numbers. The fact that Dodge built three thousand, three hundred of the crazy-insane nine-second 2018 Dodge Challenger SRT Demon, let alone over a quarter million HEMI 5.7L, HEMI 6.1L and HEMI 6.4L engine-powered Challengers since 2008, plus similar numbers of Chargers, suggests that the “good old days” are right now!

1 Comment


So was “boss hoss” a commonly used term to describe a fast car or hot rod prior to this ad? I’m familiar with a song recorded by the Sonics called “Boss Hoss” that was released in '65, so I’m assuming so…