1 bottle of fork oil will do both forks. 6 - 6 1/2 oz, depending on your preference for how it feels. I use PJ1 7 1/2 wgt in my '75 750F. I used ATF years ago, but found the fork had noticeably less stiction with the PJ fork oil. These primitive forks need all the help they can get. I tried 10 wgt once but found the action to be harsh. 7 1/2 is a close approximation to ATF viscosity.