Chuck. Yes the 427 does not have as good of a rod ratio and also I beleive the piston pin will end up in the
oil ring groove. I just built a 408 with the 4.00" stroke crank and 6.250" rod. Works out to be a decent rod ratio and the piston pin is just below the
oil ring. To short of a rod ratio will cause more side load and wear on the cylinders and
oil consumption when the pin is in the oil ring groove.
Jeff