351C/351M/400M
The 351C, 351M and 400M engines, distant cousins of the small-block series of engines, employ
different crankshafts, connecting rods and pistons. While the 351C, 351M and 400M are all of the
335-series engine family, they differ significantly internally. The 351C has a different crankshaft,
connecting rod and piston than the 351M and 400M because the M-series engines have a taller
block deck than the 351C, even though bore and stroke are the same.
Crankshafts
221/260/289/302
Ford utilized surprisingly few crankshaft types in small-block engines. The 221, 260 and 289ci
engines all used the same cast iron crankshaft, making this crank widely available. While it might be
easy to assume that the 289 High Performance engine had the same type of forged steel
crankshaft also incorporated in the Boss 302 engine to come years later, exactly the opposite is
true. The 289 High Performance engine used the same cast iron crank as the 289-2V and 4V
engines - with the only exception being that it was Brinell tested for toughness and was supported
with heavier main bearing caps. It was not a high-nodular iron crank, but simply the best of the
standard nodular iron lot.
here some info i got
answer if wrong
yes the 289 and 302 boss is high grade crank shaft
so be carefull when you look at some article on web
here why most of to day crank wear down this one no but will break insted