February 26th, 2021 Chris Phillip

In 1970, both the Mustang Mach I and the 428ci Super Cobra-Jet (SCJ) engine returned for their second year of production. When paired together, the result was a fire-breathing, sport roof-bodied Stang fit with a high-compression street brawler engine.

The strength of the legendary Super Cobra Jet engine was found in its rotating assembly; crankshaft, connecting rods, pistons, wrist pins, flywheel/flexplate, and harmonic balancer - that were all designed to withstand the higher-RPM requirements of drag racing.

The only way to get a Super Cobra Jet in a new 1970 Mach 1 was to special order either a 3.91:1 or 4.30 rear-gear ratio. Doing so would also facilitate the mandatory installation of an oil cooler into the car on the factory assembly line.

With an underrated 335 hp on tap and 440 lb-ft of torque thumping from its big-inch mill, the ’70 428 Super Cobra Jet Mach 1 would go on to be among the most desirable Mustangs of its era. Only 857 of these rare racehorses were ever built. As 1970 was the last year of the 428 SCJ as installed in Mustangs, the 428 SCJ Mach I has the looks, power, rarity, and collectability to easily earn a position in the Top 10 Mustang list.

Special thanks to www.428cobrajet.org for its assistance in the preparation of this article.

About the photo: Subtle it’s not. The 1970 Mach 1 (pronounced “Mach Won” Mustang came standard with a unique black grille with special sport lamps, a matte-black hood treatment, and aluminum rocker panels with specific callouts. When optioned with the 428 Super Cobra Jet engine, it became a race-ready ride that could take on stoplights and quarter miles with equal confidence.

Story by Rick Seitz