[350HP930]

The stock 930 ports were officially 34 mm, but in reality they were more like 33 mm.

The carrera manifold and spacers are 40+mm so even with 36 mm ports you will want to do some port matching since port flows do not like meeting sharp edges like several millimeters of port mismatch.

Don't forget about the injector notch and the gasket area right above it.