Fast Fox Here is a real link that refers to the 351HO engine.
The 351 HO engine was not availabe in 1970. It was only in the mustang during 1972.
The '72 H.O. has all the required goodies to qualify for authentic Boss status. Additional standard features include--
9 inch "N" case rear end
31 spline axles
Big input and output shaft transmission
Solid Lifter Cam (.490 lift/275 duration) (D2ZZ-A)
Adjustable rocker arms
Aluminum Intake manifold (D1ZX-CA)
Dual Point Ignition
Oversize harmonic damper (D2ZX-AA)
High output Alternator w/ big pulley
Forged Pistons w/ one valve relief cut on top (D2ZX-AA)
VIN stamped on back Drivers side of block
Shot-peened & Magnafluxed forged 1041 steel Rods (D1ZX-AA)
180,000 PSI Rod Bolts (D1ZZ-A)
Aluminum valve covers
Heavy Duty Flywheel (D1ZX-AA)
Six quart oil capacity
4-Bolt Main Bearing Cap Block (D2AE-CA)
Crankshaft-- specially selected (D1ZZ-A)
Larger exhaust manifolds (D1ZX)
While most enthusiasts gloat over the awesome 11.7 compression ratio of the '71, they forget it would be almost impossible to drive one of these cars daily on pump gas. With the lower compression of the '72 model year, daily driving is much improved. Although the 3:91 gears yield to very poor mileage, I drive my H.O. daily. Before the engine was rebuilt in March, it averaged 13 MPG on a 400 mile round trip. Not bad for 3500 to 4000 RPM most of the time.