The 354 Hemi used in the 57 Dodge D501 was the same engine as the 355 horsepower special 300B engine. However, for whatever reasons, it was listed as 340 horses in the D501. The D501, to my knowledge, used 57 300C carbs to inorder to clear the lower hood line of the 57s. There were 101 built and, strangely, most were built months after the ban on factory sponsored racing. My car was built in April of 1957. Sherwood Kahlenberg