Actually, the GSXR 750 will fit through Akropovic. The header comes in several small pieces and you will need to tweak each little peice to gain clearance under the oil pan area. I have a stick on heat shield I put on my oil pan just in case there is any rubbing. So far nothing to report, otherwise it's a direct bolt up.
One difference between the arrow made for our bike and the Akropovic made for a GSXR is the configuration off of the head. It swings away from the oil filter area. See pic in my build. It worked out great for changing oil and filter