...What you have is the 3418645 Which was used in the 318 and 360 2 bbl engines which is a pressed fit wrist pin. The heavy duty rod was used in the 340 and 360 4 bbl's and was a full floating wrist pin. ...
The "3418645" rod forging IS the heavy duty rod. Used in 318's and 360,s since about 1972, including 340's.Only 340's used the full floating, bushed ends on the heavy rods. All 360's were the heavy forging using pressed pins, including HP 360's.The early rod forging is 2406782 and is bushed for early 318's and all 273's.