360
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.
Like I expllained, the book had some conflicting information when I read and compared the text, the illustrations and text, and the charts.
They said that the same rod was used in the 360's, 340's and 318's after 72. However the chart says that the 73 340 rod was the 2899495 forging which was floating. They don't list a press fit rod for the 340.
Did the 72 & 73 340's have press fit or floating rods from the factory?
Then the chart says that the 318 used the 340 rod 2899495 in 72 & 73, then changed to the 3418645 (360 press fit) rod in 74.
According to the chart, the 340's only had a floating pin, not a press fit pin. So then how did they use the same rod as the 360?
Then the picture shows the heavy duty rod on top and the "light duty" rod on the bottom. The text underneath states that the heavy duty rod was used in the 340 and 360 4 bbls and the light duty rod was used in the 273, 318, & 360 2 bbl.
The chart does not show a press fit rod for the 273, only floating.
So that leads me to question. Did the 340 have press fit or floating rods in 72 & 73?