Yes, i've used the offset keys and offset bushings in many engines where I had customers that didn't want to spring for an adjustable timing set. More times than not though, the cam timing events wont correspond accurately when you install a cam in the "straight up" orientation, because as with the "theoretical" rocker ratio, they also are assuming "perfect world" scenarios where all things are in perfect sync. Many aftermarket stock replacement timing sets for a lot of different engines are also designed to purposely retard the cam timing as much as 8° or more for emissions purposes(Fords being one of them), so its best to always verify and not assume you are close to what the cam card says.
