Upper Intake; Heads; Cams; Headers - Factory Five Racing Mk4 Roadster Assembly Manual

Upper Intake

The next logical step for breathing is a more free flowing intake manifold. There are a number of
intakes available from different companies (e.g. Edelbrock, Trick Flow). Ford also makes a good
intake, the cast 1993 Cobra intake from Ford Racing.

Heads

The 5.0L Mustang aftermarket is full of aluminum and cast iron heads for the small block Ford. Our
favorites are the Edelbrock Victor Jr. and the AFR aluminum heads. These both flow very well, have
stock exhaust port heights which allows the use of our headers and not only give you extra horsepower
but also remove 50 lbs. in the process.

Cams

If you need to pass emissions testing, use a cam with a CARB number. We like the Ford E303 cam.
We have used it with success in our racecars both naturally aspirated and in boosted applications. If
building a more radical engine, match the cam to the combination.

Headers

Stock 1987-1995 Mustang: 1½" OD
We've found that the Mustang factory headers work well for the stock engine. If you want to go to an
aftermarket set, the 1⅝" MAC shorty unequal length headers or Ford Racing 1⅝" unequal length
headers fit as bolt on parts. They will reward you with an approximate 5-10 hp bump in the top end. All
aftermarket headers use mandrel (smooth consistent bends) bent tubing. The stock ones are not and are
restrictive on non-stock engines.
If using a 351W engine there are two options, use 351W engine swap headers from Ford Racing (M-
9430-A58) or MAC (E358692) or if smog/catalytic converters are not necessary, use our full length 4
into 4 headers.
Stock 1996-2004 Mustang: Cast iron manifolds
Ford Racing offers 1⅝" unequal length Stainless Steel headers that are bolt on parts. They will reward
you with a nicer look and a small horsepower increase.
4.6L 2 valve FRPP # M9430-E462
4.6L 4 valve FRPP # M9430-E464
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