I couldn’t find anything online that differentiates between “boxer” and “horizontally opposed” - and saw lots of sites that say “both Porsche and Subaru use boxer engines”, so it seems like the terms are synonymous and have nothing to do with firing order. If anyone can provide a reference to something explaining it with with more detail, I’d love to read about it.

That said, you can check the Lego model against the 911 firing order: 1-6-2-4-3-5 … 1 / 4 are closest to the back of the car (non-flywheel side). 1,2,3 is on the left, 4,5,6 on the right.

The only place to get raw Turbonite is from moon rocks, so pricing seems totally reasonable.