Editing Ford 335 engine (section)

==={{vanchor |1971 R-code}} (Boss 351)===
The Boss 351 was the most potent high-performance variant of the 351C available only in the 1971 Boss 351 Mustang. Rated at 330&nbsp;bhp (246&nbsp;kW), it was fitted with a four-barrel [[Autolite 4300 carburetor#4300D.2C 715 CFM spreadbore .281971-1974.29.5B1.5D|Autolite model 4300-D]] spreadbore carburetor, an aluminum intake manifold, solid lifters, dual-point distributor, a six-quart oil pan, and cast-aluminum valve covers.<ref name="Cleveland"/><ref name="Hemmings Mustang"/> [[Forging|Forged]] domed [[piston]]s gave an 11.1:1 advertised [[compression ratio]] which made premium fuel necessary.<ref name="71 Mustang Brochure"/><ref name="Boss Registry 351C"/> It had four-bolt main bearing caps selected for hardness and a premium cast-iron [[crankshaft]] selected for hardness (90% [[nodular iron|nodularity]]).<ref name="Cleveland"/> The [[cylinder head]] was modified for better airflow, used screw-in studs with adjustable rocker arms, and except for the water passages and larger combustion chambers, were very similar to the heads used on the Boss 302.<ref name="V-8 Data Book"/> The valve train used hardened and ground push rods with guide plates and single groove, hardened valve split locks.<ref name="Cleveland"/> The forged [[connecting rod]]s were shot-peened and [[magnaflux]]ed for strength, and used improved durability 3/8-inch nuts and bolts.<ref name="Cleveland"/> The R-code Boss 351 was only installed in the 1971 Boss 351 Mustang, and it came equipped with Ram Air induction. Ford manufactured 1,806 Boss 351 Mustangs in 1971, 591 of which are registered and accounted for on the Boss 351 Registry site.<ref name="Boss Registry">{{cite web|title=Welcome to the Boss 351 Registry|url=http://www.boss351registry.com/|website=Boss 351 Registry}}</ref>

The January 2010 issue of [[Hot Rod (magazine)|''Hot Rod'']] reported a project in which a Boss 351 was assembled to the exact internal specifications of an original motor, but fitted with open, long tube, 1-3/4-inch Hooker headers (vs. the stock cast-iron manifolds), a facility water pump, a 750 Holley Street HP-series carburetor (vs. the stock 715 CFM Autolite unit), and minus the factory air filter assembly, engine accessories, or factory exhaust system. In that externally modified state it produced {{cvt|383|hp|kW|0}} [[Horsepower#SAE gross power|SAE gross]] at 6,100&nbsp;rpm, and {{cvt|391|lbft|Nm}} torque (gross) at 4,000&nbsp;rpm.<ref>{{cite journal|url=http://www.hotrod.com/techarticles/engine/hrdp_1001_muscle_car_engine_shootout/ford_boss_351_chevy_lt1_350.html|title=Muscle Car Engine Shootout - Ford Boss 351 Vs. Chevy LT-1 350|journal=Hot Rod Magazine}}</ref> A measurement of [[Horsepower#SAE net power|SAE net]] horsepower would be significantly lower, and represents a more realistic as-installed configuration with all engine accessories, air cleaner assembly, and automobile exhaust system.