We use the top center method to measure cam timing. The engine is turned to a few degrees from maximum valve lift and the turning is stopped and the lift and the degrees are noted. Then the engine is rotated past maximum lift and when the valve lift is the same as the first time noted, the degrees are noted. The degrees are added and divided by two which gives you an accurate estimation of the point of maximum lift. This can be compared to the cam card. Typically the cams can end up being too retarded as head surfacing and block decking have that effect. If this is going on, it is corrected by using the adjustable cam gears.
Here is what the VVEL system looks like. A lot of complicated parts are going on here!
This is what the stepper motor control for the VVEL system looks like.
The VVEL control motor and linkage are installed one per head.
Next the valve covers are installed.
Then the front cover is put in place.