Specifications
1971 'Duster 340'......................................................................1971 Mustang 'Boss 351'
Shipping Weight.......... #3165 lbs............................................. #3281 lbs.
Curb Weight................ #3310 lbs............................................. #3430 lbs.
340__________________________________________-____351
Bore..........4.04"....................................................................... 4.00"
Stroke...... 3.31"....................................................................... 3.50"
275 HP 'Factory Rated'............................................................. 330 HP 'Factory Rated'
275 HP @ 5000 RPM's.............................................................. 330 HP @ 5400 RPM's
340 Ft/Lbs. of Torque @ 3200 RPM's....................................... 370 Ft/Lbs. of Torque @ 4000 RPM's
Tach Red Line............... 5500 RPM's....................................... 6150 RPM's
{ 310 HP 'NHRA' Rated }......................................................... { 330 HP 'NHRA' Rated }
1971 NHRA Class... G/S or SS/I............................................... F/S or SS/I
Compression........ 10.3 to 1..................................................... 11.3 to 1
Piston................... Flat-Top w/2 Notches................................ .315" Dome
Type..................... Forged Aluminum....................................... Forged Aluminum
Piston Height....... +.045 'Above Deck'..................................... -.008" 'Below Deck'
Crankshaft.......... Forged Steel................................................. Cast High-Strength Nodular
Rods................... Forged.......................................................... Forged ~ Shot-Peened and Magna-fluxed
Piston Pins......... Full-Floating.................................................. Pressed-Fit
Rod Bolts............ 3/8".............................................................. 3/8" ~ Special Length and Hardened
Cylinder Head...... #3418915 'J' Head...................................... D1ZE-B
CC Chamber......... 68.0 to 73.0 {Factory}................................ 67.6 {Factory}
CC Minimum........ 63.3 CC {NHRA}.......................................... 64.6 CC {NHRA}
Intake................. 2.02"............................................................ 2.19"
Exhaust............... 1.60"............................................................ 1.71"
Intake Port Size.. 1.16" x 2.27" ............................................... 2.50" x 1.75"
Exhaust Port Size 1.25" x 1.75"................................................ 2.00" x 1.74"
Intake Volume.... 157 CC.......................................................... 244 CC
Exhaust Volume.. 73 CC............................................................ 136 CC
Camshaft............ 'Hydraulic'..................................................... 'Mechanical'
Lift...................... .463"/.472" {NHRA specifications}.............. .502" / .502" {NHRA Specifications}
Duration.............. 276*/284*................................................... 290* / 290*
Overlap............... 52*............................................................... 58*
Valve Springs...... #134 lbs. 'Closed'......................................... #93 lbs. 'Closed'
Valve Springs.......#235 lbs. 'Open'........................................... #315 lbs. 'Open'
Rocker Arms........ Stamped-Steel Non-Adjustable.................... Stamped Steel 'High-Strength' Adjustable
Intake................. Cast Iron 360* Dual-Plane High-Rise........... Cast Aluminum Dual-Plane High Rise
Carburetor.......... Carter Thermo-Quad {800 CFM}.................... Autolite #4300-D {750 CFM}
Throttle Bore...... 1.375" Primary ~ 2.250" Secondary............... 1.563" Primary ~ 1.960" Secondary
Venturi............... 1.063" ~ Air-Valve.......................................... 1.250" ~ Air-Valve
Distributor......... Dual-Point....................................................... Dual-Point
Air Cleaner........ Unsilenced....................................................... Ram-Air Induction w/Twin 'NASA' Hood Ducts
Exhaust Pipe...... 2.25".............................................................. 2.50" Primary w/H-Pipe ~ 2.25" Secondary
Transmission..... 2.44 / 1.77 / 1.34 / 1.00 {A-833}.................. 2.32 / 1.69 / 1.29 / 1.00 {Close-Ratio}
Clutch................ 10.5".............................................................. 11.0"
Pressure-Plate.......................................................................... 3-Finger
Flywheel............ 27 lbs. ........................................................... 27.3 lbs.
Shifter............... Hurst Linkage.................................................. Hurst Shifter
Gears................ 3.91 'Sure-Grip' {Optional}.............................. 3.91 'Traction-Loc'
Rims................. 14" x 5.5"......................................................... 15" x 7"
Tires................. E-70 x 14" Goodyear Polyglas GT...................... F-60 x 15" Goodyear Polyglas GT