Yep, it’s out of an FSM. I looked it up awhile back for yet another cooling thread to show the factory pulley ratios and what water pump went with them. I think it’s the ‘68 or ‘69 FSM. Some of the later ones have the chart too but they don’t list all the engines, the 273’s went away and then later they big block specs dropped off, that particular FSM has all the different engines. The ratios didn’t change through ‘74 anyway.
