9500-10k is plenty to squeeze out everything you need from a street engine. At 9500 your butthole puckers awaiting a rod to come flying through the firewall. Build an engine to turn that and see if you still feel the need to turn it higher. Not only that, the head on a b series engine will only flow to a certain rpm. My head made power to one of the highest points I have ever seen from a factory b16 head. I made power out to 9200 rpms and flattened out to 9700. The headwork and cams(monster lift/duration: no idle for u) you would need to turn 13000 effectively would not be worth the costs.