Ford Mustangs grew to their all-time largest for the 1971 model year. Wheelbase was up an inch to 109, length increased 2.1 inches to 189.5 and width grew 2.4 to 74.1. The latter was accompanied by a tread increase to allow the 429 cid big-blocks to fit with ease.
Though the 429-powered cars were the most muscular, the Boss 351 was the most interesting. The Boss 429 was curtailed early in the 1970 model run and the Boss 302 was of no more use after it was over. Engine sizes were no longer critical to racing legalization, so the Boss 351's purpose was just to tap what was left of the declining performance market.
Like its predecessors, it was based on the Sportsroof fastback. It was considered an option and brought the $2,973 base model up to $4,124. The heart of the new Boss was a 351 hp Cleveland V-8 with four-bolt main bearings, solid iifters and a four-barrel carb. The 1971 models were the last for Ford high-compression engines and the last for gross advertised horsepower numbers, which came to 330 hp on the Boss.
Other mechanicals included a fourspeed top-loader transmission with a Hurst shifter, competition suspension, power front disc brakes, 3.91:1 Traction-Lok gearing, dual exhaust with non-exposed tips and the infamous rev limiter. Visuals were plentiful with side and rear identification decals, a matte black hood with functional scoops and locks and side stripes.
Only about 1,800 Boss 351s were made, making them rare today. There was no 1972 Boss of any kind, but by playing with the option list, you could come close. The last year for the big Mustang was 1973.
Major Standard Features
Standard Boss 351 Features Include:
The Boss 351 includes all of the interior features of the SportsRoof plus an instrument panel instrumentation group that includeds tachometer, trip odometer, "OIL", "AMP" and "TEMP" gauges.