1968 428 Cobra Jet Drag Strip Modifications

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The March 1968 edition of Autolite Shop Tips includes a comprehensive description of the modifications made to prepare the 1968 428 Cobra Jet engine for drag strip duty in the Stock and Super Stock classes. Here's a summary (part numbers are service part numbers unless noted as engineering part numbers):

ComponentProduction"C" Stock"E" Super Stock
Cylinder HeadC8OZ-6049-F
Engineering Number C8AE-6090-J
SameSame
Intake Manifold
(Aluminum)
C6AZ-9424-H
Engineering Number C7AE-9425-F
SameOffset 427
C6AZ-9424-M
Engineering Number C7AE-9425-C
Intake Manifold
(Cast Iron)
C8OA-9424-A
Engineering Number C8OE-9425-A
SameN/A
Carburetor, Manual
(735 cfm)
C8OZ-9510-AASameSame
Carburetor, Automatic
(735 cfm)
C8OZ-9510-ABSameSame
CamshaftHydraulic
C6OZ-6250-B
Hydraulic
C8AX-6250-C
Solid
C8AX-6250-D
Valve SpringNot Specified427 Type
C5AZ-6513-A
Crane or H-M Type
spring, retainer, push rod, and tappet
Rocker ArmNon-Adjustable 1.73:1
B8AZ-6564-C
Adjustable 1.76:1
B8A-6564-B
Adjustable 1.76:1
B8A-6564-B
Adjustable 1.76:1
B8A-6564-B
Exhaust ValveC3AZ-6505-ESameLightweight, Sodium-Filled
C8AX-6505-B
Intake ValveC3AZ-6507-AJSameLightweight, Hollow Stem
C8AX-6507-B
Valve LifterHydraulic
Part Number C3DZ-6500-B
Hydraulic
Part Number C4TZ-6500-A
Crane Lightweight or
427 Type C4AZ-6500-B
Piston
(Cast Aluminum)
C6AZ-6108-AY, 10.7:1 CRForged, Dished/Eyebrows
11.0:1 CR
Forged, Flat top/Eyebrows
11.6:1 CR
Piston RingsC6AZ-6148-AMoly TypeMoly Type
Piston RodsP.I. Type
C6AE-6200-F
427 Type
C5AZ-6200-D
427 Type
C5AZ-6200-D
427 Type
C5AZ-6200-D
CrankshaftC6AZ-6303-B1SameSame
Oil PanC6OZ-6675-ADeep sump 9-quart
C5AE-6675-N
Same
Oil PickupC6OZ-6622-AC5AE-6622-CSame
Oil FilterC1AZ-6731-ALow Resistance
C8AE-6714-B
Same
DistributorC8OZ-12127-DDual point, 427 Type
C5AZ-12127-E
Same
Exhaust SystemNot SpecifiedJardine or Doug's Type headersSame
Vibration DamperNot SpecifiedHeavy Duty 427 TypeSame
ClutchNot SpecifiedProduction Auto. and ManualHeavy Duty #2650 Type
Transmission2.32, 1.69, 1.29 ratiosProduction/blocker rings cut
Line lock
Same
Rear End3.89:1, no locker4.44:1/242L Detroit Locker4.71:1/242L Detroit Locker
SuspensionNot Specified32" traction bar right side
Single link bar left side
32" traction bar both sides
ShocksNot SpecifiedHeavy Duty TypeSame
TiresF70 Firestone8.90x14, 7" Tread10.50x15

Shipping weight: AMA's Mustang fastback 3267 lbs., hardtop 3243 lbs.