Jim Smart
September 17, 2012

What we learn from both of these engines is what's possible from original equipment Ford castings, and it gives us a strong sense of what Ford engineers faced a half century ago. Though we have rare and desirable parts among these beasty 427s, imagine what they could do with better cylinder heads and induction. Ford's own 427 High Riser heads and induction would be a good start, though you'd lose torque on the low end.

The aftermarket offers a wealth of great cylinder heads and induction systems for the FE depending on your expectations and budget. Because these 427s had to be assembled as original-appearing FE mills utlizing factory castings, they suffer from the limitations of Medium Riser dimensions (2.18-/1.72-inch valves with 2.78x1.38-inch intake and 1.78x1.30-inch exhaust ports. With these heads, you get good low to mid-range torque, but not the full potential on the high end because they are basically a street/race head. The aluminum "XE" advantage isn't so much breathing, but instead great heat sink capability to where you can run a pinch more timing, higher compression, and a slightly leaner mixture depending upon what you get for a plug reading. This is where dyno time is money well spent before placing your FE between the shock towers. But that is another story. Check out the captions to see just how these two vintage V-8s faired in the dyno cell.

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Two FEs--One Polygraph Room

This was an opportunity to dress a 427 up in its original clothing void of special modifications--basically Ford's legendary Cobra FE 427 as it was in the mid-1960s when it powered the world's fastest production automobile. We wound up with 510 hp and 503 lb-ft of torque. This is what JGM got from a basically stock 427 FE with rare metal on top. Horsepower and torque numbers aren't much different than you would have seen in 1966, and the gains aren't all that significant with the aluminum heads and magnesium intake. Aluminum heads allow us to run more timing and less jetting in an effort to gain power. Further gains could have been achieved with a more aggressive roller mechanical camshaft, larger carburetor, and richer jetting. Jim and Jeff followed instinct and went with what they knew works. Here are some of the more significant pieces JGM specified for this circa '66 427.

JE custom forged pistons with race ring set(No Part Numbers)
ARP connecting rod bolts200-6001
Fel-Pro gaskets and seals throughout
Comp Cams flat tappet mechanical camshaft custom grind33-000-5
Comp Cams valvesprings972-16
Comp Cams lifters810-16
Sealed power rocker shaftRS-621
Pro-Gear high-performance timing setPG4108
Melling high-volume oil pumpM-57HV
ARP oil pump shaft154-7902
AMK Products cylinder head bolt kitF-1771
AMK Products engine bolt kit660-427HP
C5AE-H experimental aluminum heads2.18/1.72-inch intake/exhaust
C6AE-J 427 side-oiler block with SOHC drain holes
Magnesium dual-plane medium riser inductionNo Part Number
"XE132391" steel crankshaft with Welsh oil galley plugs and C-clips
C6AE-E cap-screw connecting rods with ARP boltsalso 428 SCJ

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