The Torrington bearings on the shaft was a pain but all worked out, Finally broke a shaft after 25 years and had 2 new ones made.
I calulated 1.70 on the new rocker but came out with 1.63. The roller tip ends eliminated this and I have never replaced the guides since. The reason I made my own roller rockers was because I was wearing out valve guides every 2 years. All this is do able during assembly just takes some time. This gives you the lift with the newly ground cam but you still need to check the angle at zero lift and at full lift. Most of the time if you are making a 'big' cam off an original, hopefully steel, the base circle is smaller and this throws off everything angluar. After working with valve lash caps and machining the aluminum base rocker stands to make sure at 1/2 cam lift the rocker arm was level I actually was able to get more. 850 at the valve then divided it by 1.7 you would have. When I first checked lift at the valve and measured the actual cam lift I cam out with a 1.41 ratio using a cam that had. If the engine is assembled you can check the lift at the valve and then try dividing that by 1.7, 1.6, or 1.5 and see which ratio matches your actual cam lobe lift.