FordRacingParts.com
SMALL BLOCK V-8 HYDRAULIC ROLLER TAPPET CAMSHAFTS
M-6250-Z303*
This part is no longer available.

tech notes

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.

specs

Package Dimensions:
2.5 x 2.5 x 25
Package Weight:
9.6 lbs
Part Type:
Engine: Cam/Tappets/Pushrods
Instruction Sheet:
Not Available
Warranty Availability:
Not Available
Country of Origin:
United States
UPC Code:
756122625545
Catalog Page Number:
0