The boss 351 in 92 and 95 inch deck heights is a more modern block with superior alloys oiling and casting procedures combined with modern and precise. Of the three boss mustangs the boss 351 definitely borrowed a lot of its external styling from the mach 1.
Straightening Out Ford S 351 Ci Engines Reincarnation Magazine
Boss 351 block hp rating. V 8 water cooled cast iron block and heads. Engine blocks from both stock and aftermarket blocks. While the 302 is a small block and the 429 is a big block the 351 falls right in between the two offering more displacement but with the engine block size and weight of a small block. Compression dropped to 801. Stepping up to the larger boss 351 resulted in peak numbers of 383 hp at a slightly lower 6200 rpm and 391 lbft of torque at 4000 rpm. The two barrel version was rated at 160 horsepower.
Horsepower rating for this engine was 266 at 5400 and torque was 301 at 3600. The boss 351 engine shared a similar fate. The other answer is more to the point. The four barrel was rated at 266 horsepower. Gone was a great motor. It will bolt in place of a 289 or 302.
Ford cut the horsepower in 1971 to a mere 330 and yet with only 351 cubic inches the boss 351 would run withor some say ahead ofthe big block 429 with 375 hp. 351 cu in 5750 cc power. The more i read the more the 351. Technological improvements such as splayed main bolts siamesed bores with engineered coolant cross drilling front crossover lifter oiling and diesel grade iron with 41000 psi tensile strength separate ford performance parts boss 351 cid. The boss 351s main claim to fame was its r code v 8 whose 330hp at 5400 rpm and 370 lbsft. 370 lb ft at 4000 rpm.
Of torque at 4000 rpm would outgun a number of big blocks. The boss 351 mustang was dropped but the boss 351 engine was carried. Even today the 351 is an engine of choice. But the engine was just the beginning of the bosss goodness. 330 hp at 5400 rpm torque. The pistons were dish topped.