The number I used several years ago is no longer available and I'm not sure what's being used these days. I believe the SyTy guys do injector driver upgrades fairly often so you might want to look around at code59.org. I've posted links to a web page before with upgrade instructions for a 7749. The 7730 is similar but only one driver. I *think* Bill Shaw was the man who posted the howto that I linked to.