Jon,
I doubt if they can answer the question. The instructions are a wee bit basic.

Are you using a Hyde mount? All you are really doing is lining up the cowl/engine relationship.

Either way, on the last two Quests that I built I fitted a firewall and had to figure out the mount position.

First, I taped the cowl in position so that it matched the "lines" of the side view and from above.

Then with a "cross-bar" and a set-square I located the center line by measuring back from the position of the nose ring.

Just lay a short steel ruler horizontally across the nose-ring opening.
Then put the square through the hole until it touches the firewall.
Adjust the square to just be short of that depth.
Place the square on the center of the x-bar. (Spinner opening center)

Now you can see where the horizontal center should be.

Do the same thing in the vertical plane and you can mark the height as well.

You can see through the cheek cowl holes or, as in my case, pre-cut the rear of the cowl for air ducting.

The square that I use is the woodworkers type that has a sliding ruler section in it.

If you are not sure just call me.

Eric.

P.S. A always use Bolly FAI gear. It's lighter and flexes better on landings :-)