Chrysler was trapped by the success of the 426 Race Hemi. It was such a dominating force in NASCAR that the homologation rules were changed (rule changes tended to follow closely behind Chrysler technology breakthroughs). Instead of building race Hemi engines in the hundreds, the rule change mandated building them by the thousands. That was too expensive of a proposition, so Chrysler sat out the 1965 NASCAR season.
For 1966, Chrysler detuned the race Hemi to produce the street Hemi. The two versions were very similar, with changes to the street Hemi having to do with making it more drivable on the street. The most significant changes were to the intake and exhaust manifolds and the valvetrain. The camshaft and related components were toned down. Different pistons lowered the street Hemi compression ratio from 12.5:1 to 10.25:1.
The street Hemi used an aluminum dual quad intake manifold that placed the two Carter four-barrel carburetors in tandem, instead of side-by-side as on the race Hemi. Even after being “de-tuned,” the street Hemi still produced 425 horsepower and 490 lb-ft of torque.
In spite of all the modifications to make the street Hemi more streetable, it was still a pretty cold-blooded engine that was hard on spark plugs. Street Hemis needed pretty constant tuning to keep them at peak performance levels. The street Hemi was also an expensive option, so 1966 and 1967 Hemi Mopars are relatively scarce. The street Hemi was available in the Dodge Charger, the Dodge Coronet and the Plymouth Belvedere.
Even though the engine was introduced in 1966, more was done to promote the engine in 1967. The Dodge Coronet gained the R/T (for road and track) model and Plymouth debuted the GTX. These two B-body cars are very similar. They were marketed as full-size, upscale hardtops with a strong performance flavor. The base engine was the 375-horsepower 440, and the only optional engine was the 426 street Hemi.
Dodge had both the Charger and the Coronet R/T. The marketing people considered the R/T as the performance car and a GTO competitor, while the Charger was more of a luxury/performance/touring car. There were physical similarities between the two cars. The R/T grille resembled a Charger grille, but with permanently open headlights. Fenders, quarter panels, and doors were all obviously styled alike. The R/T got its own faux hood vents/scoops. The interiors of the two cars had many similarities.
The TorqueFlite automatic was standard. Our feature 1967 Coronet R/T belongs to Paul Phillips and is equipped with the optional center console, console shifter, and console mounted tachometer. Paul’s Coronet has the rare street Hemi. Most Coronet R/T engines were 440s. The vast majority of 1967 Coronet R/Ts were hardtops, but a convertible was also available.