Steve Baur
Former Editor, Modified Mustangs & Fords
May 1, 2009
Photos By: Competition Products, Jason Combs
The Fast As Cast cylinder heads offer up a 190cc intake runner volume, while the exhaust measures 66 cc.

Rounding out the induction side of the 331 is TFS' 5.0L R manifold, a BBK 75mm throttle body, and a TFS Trackmax Stage 2 camshaft to move the air in and out. Best of all is that you can order all of the parts from just two places, and with the same-day shipping from Competition Products and Summit Racing Equipment, you can have the combination built and shoehorned into your street machine in no time at all.

This month, we're bringing you the buildup of the engine; then we'll follow up with an engine dyno test, a chassis dyno test, and conclude with a quarter-mile drag test. You'll get to see what the parasitic loss is from crank to wheel horsepower, as well as how this stock-block stroke swap performs in a Fox-body Mustang at the track.

The combustion chamber volume is still the standard Twisted Wedge 64cc, though the heart-shaped chamber does receive a CNC cut that is said to improve mid-lift numbers.

Cylinder-Head Flow Numbers
Tested on a 4.030-inch bore. Flowed at 28 inches on a Superflow SF-600Lift

Lift IntakeExhaust
0.{{{100}}}71{{{57}}}
0.{{{200}}}145115
0.{{{300}}}214150
0.400257187
0.500268194
0.{{{600}}}273197