If your intake manifold can support the type of CFM... And if your camshafts are designed to provide the kind of lift, duration, and overlapping to make power at higher RPM? Then, like others have said, hardware tolerance and specifications... But perhaps most importantly, you'd want a big bore, low stroke design to start with, otherwise you'll be having too much vibration and breaking too many parts along the way to 13,000 RPM.

 

Well after a ****eload of dyno runs, and drag runs, the only thing they seem to break is the gearbox, and thats running a 6 speed Airshifted Hollinger box worth 20 grand australian... everything else has stayed up for now