Details

• Product ID:

  M-6250-X303

• Description:

  The legendary B303 cam developed by Ford Racing for the 5.0L Fox-body Mustang. This cam provides a noticeable power improvement and lumpy idle while maintaining good driveability with a manual transmission. Works well with carburetors or mass air fuel injection.

  • Fits 1985 and later 302 roller cam blocks
  • Will also fit 1963 – 1984 non-roller cam 289-302 blocks when used with hydraulic roller lifters M-6500-T58
  • Will also fit 1994 –1997 351W blocks with factory roller cam
  • Will also fit 1969 – 1993 non-roller cam 351W blocks when used with hydraulic roller lifters M-6500-T58
  • Requires upgraded valve springs. For stock cylinder head applications use M-6513-A50 valve springs installed at 1.820". For aftermarket cylinder heads M-6513-BH recommended.
  • Valve spring requirements: 120 lbs valve seat pressure minimum 295 lbs open.
  • On EFI engines, performance camshafts work only with mass air induction systems. Will not work with Explorer EEC-V EFI or speed density EFI systems.
  • Also fits 1994-97 351W with factory roller cam when used with mass air EFI.
  • Stock 5.0L HO cam advertised specs are 266°/266° duration, 0.444"/0.444" lift.
  • Higher stall torque converter recommended for automatic transmission

  PART NUMBER	ENGINE	ROCKER RATIO	INTAKE EVENTS (0.050")	EXHAUST EVENTS (0.050")	DURATION (SAE)	LIFT (INCHES)	LOBE CENTER
  OPEN	CLOSE	OPEN	CLOSE	INT.	EXH.	LOBE	VALVE	INT.	EXH.
  M-6250-B303* (1)(2)(3)(6)	1985 and Later 302 Roller Cam	1.60	5° BTC	39° ABC	49° BBC	5° BTC	284°	284°	.300 I	.480 I	107°	117°
  224°	224	.300E	.480 E
  M-6250-E303 (1)(2)(3)(6)	1985 and Later 302 Roller Cam	1.60	0° BTC	40° ABC	40° BBC	0° BTC	282°	282°	.311 I	.498 I	110°	110°
  220°	220°	.311E	.498 E
  M-6250-F303* (1)(2)(3)(4) (6)(7)	1985 and Later 302 Roller Cam	1.60	4° BTC	42° ABC	52° BBC	6° BTC	288°	288°	.320 I	.512 I	109°	119°
  226°	226°	.320E	.512 E
  M-6250-X303* (1)(2)(3)(4) (6)(8)	1985 and Later 302 Roller Cam	1.60	5° BTC	39° ABC	49° BBC	5° BTC	286°	286°	.339 I	.542 I	107°	117°
  224°	224°	.339E	.542 E
  M-6250-Z303* (1)(2)(3)(4) (5)(6)(9)	1985 and Later 302 Roller Cam	1.60	7° BTC	41° ABC	51° BBC	3° ATC	290°	290°	.345 I	.552 I	107°	117°
  228°	228°	.345E	.552 E

  NOTE: Camshaft intake and exhaust valve events are measured at 0.050" tappet lift. The duration figures in the shaded area are taken at 0.050" tappet lift. This is useful to check the cam with a degree wheel during installation. The solid color is advertised duration. For comparison purposes, add intake and exhaust lobe centers and divide by 2 to calculate "camshaft centerline" specification for Ford Racing camshafts.

  NOTES: (1) On EFI engines, performance camshafts work only with mass air induction systems. Will not work with Explorer EEC-V EFI. (2) Also fits 1994-97 351W with factory roller cam when used with mass air EFI. (3) Stock 5.0L HO cam advertised specs are 266°/266° duration, 0.444"/0.444" lift. (4) May require piston modification for piston-to-valve clearance. Valve clearance should be checked. (5) May require longer pushrods. (6) Hi-Stall torque converter recommended for automatic trans. (7) Great for superchargers. Manual transmission recommended. (8) Good torque and power up to 6200 RPM. Manual transmission recommended. (9) Good torque and power up to 6500 RPM. Manual transmission recommended.

• Condition: New