Big Block FE Series
Once you begin to understand the workings of the “FE” series big-blocks, it becomes easier to
match the right components for mighty impressive performance. The beauty of the “FE” is its
interchangability and simple dimensions throughout. All “FE” crankshafts have 2.7488-inch
main and 2.4384-inch rod journals. This makes crank swapping a breeze. The only hang-ups
are 410 and 428ci engines, which are externally balanced, unlike the rest of the “FE” engines
which are internally balanced. This means that if you intend to interchange components, you
must balance your mill accordingly or face serious vibration problems later. The 428 Super
Cobra Jet mandates further balancing considerations due to its add-on counterweight and
heavier LeMans rods.
in length; and the short rod, which is 6.488-inches. And there are four stroke dimensions—
3.30-, 3.50-, 3.784- and 3.984-inches, resulting in four basic crankshaft types. When these
strokes are combined with specific cylinder bore sizes, we come up with different
displacements.
The shorter strokes, 3.30- and 3.50-inches, belong to the smaller “FE” big-blocks, the 332,
352, 360 and 361. The longer stroke dimensions, 3.784- and 3.984-inches, belong to the 390,
406, 410, 427 and 428ci engines. The 3.30, 3.50- and 3.784-inch engines rev high. The 3.984-
inch stroke engines, the 410 and 428, don’t rev as high because they are limited by stroke.
With stroke comes torque, however—lots of torque.
Likewise, flywheels, harmonic balancers and accessory drive pulleys are quite involved as well
for the FE-series big-blocks.
The 385-series big-blocks, the 429 and 460, are much easier to understand and remember
than the “FE” engines because just two displacements were offered. The 429 and 460 use the
same length connecting rod—6.6035-inches. Displacement difference comes from the
crankshaft only. All of the 385-series big-blocks are internally balanced, which means
interchangeability is unlimited.
332/352/360/361/390
These “FE” series engines all employ a cast iron crankshaft. The only real different is stroke.
The 332 crankshaft has a 3.30-inch stroke. Three castings were made during the life of the
332. All are interchangeable. The 352 is more involved, but just as interchangeable. Fourteen
variations of the 352 crank were produced. The 360ci engine, available only in pickup trucks,
used two crankshaft types during its 1968-76 service life. The Edsel 361 was produced with
two crankshaft types during its two-year run. The 390, which arrived on the scene in 1961,
employed 16 different crankshafts through 1976.
If you are seeking a forged steel crank for your 352/360/390/406/427 engine, you may opt for
an “FT” crank from the 330HD, 361 or 391. These engines, like the 410 and 428, are
externally balanced. This means proper balancing procedures must apply in your build. Where
the steel crank suffers to a certain degree is weight because there is considerable weight gain
both in the crank and flywheel. The weight increase in the crank is due to larger
counterweights. The “FT” crank also has a larger 1.750-inch front shaft versus 1.375-inches
for the “FE” shaft. The trick here is to turn down the “FT” shaft or opt for the “FT” timing cover,
harmonic balancer and pulley.
With these engines, there are a variety of crankshafts encompassing two stroke lengths—
3.784- and 3.984-inches. The 406 and 427 employ the shorter 3.78-inch stroke also common
to the 390. The 410 and 428 utilize the longest “FE” stroke of 3.98-inches. These two engines
are externally balanced, unlike the 406 and 427 which are internally balanced.
identified via the casting/forging number
on the journal as shown. This is a cast
crank, identifiable by its parting lines on
the journals and counterweights.
journals) like this one. Later on, these cranks
had screw-in plugs.