The same guys are currently making MacPostFactor for Mavericks, but until it's out, here's copy/paste of a guide from Macrumors, together with links bellow! It works great, i'm typing from my Mac Pro 1,1 (firmware hacked to 2,1 gen) running Mac OS 10.9 Mavericks!.Many users have have great success with these methods. There are hacks such as Macpostfactor and others that can be used to place Mountain Lion, Mavericks, Yosmite and even El Captain on unsupported Macbooks, iMacs and even older machines.
