Adding eprom to ECU?

Does anyone know how well an eprom would do? Or maybe I should say does anyone know if this would work on an American 95 626? http://cgi.ebay.com/ebaymotors/Ford-Probe-Mazda-MX6-626-KLZE-Performance-Chip-Eprom-GT_W0QQcmdZViewItemQQcategoryZ33597QQitemZ8024592771QQrdZ1 I have the American motor...not the KLZE, but then it says that it converts the American ECU's into the Japanese KLZE specs. So I'm wondering what's up with that....

ask the seller ive never heard of it