the firewall is angled for thrust correction.
the engine will be off to one side and slightly higher


The firewall has side and downtrust built in
The holes should be drilled as marked or in the pattern of your engine, close to the layout per pic.
Its mounted offset but the hub of the engine will be close to the center of your cowl front opening once the cowl is mounted. its best to trial fit everything. If the holes dont work out, get a hardwood dowel and drill/fill the mistake, and startover.
Spend the time here to get it lined up