I've heard the 568 is much easier to shift, and shorter throws too. But it is a pain in the ass to install. The 555 is probably stronger, but I'm not positive about that. I just know that when someone gets into making serious power with the 2.2 or 2.5 turbo cars, they go with the 555. You can find them on EBAY every now and then, but the go for a lot of $$$. Otherwise, a 568 you might be able to find in a junkyard, it's a lot easier to find then a 555. I am waiting, very patiently, for a 555. I will only buy when a good opportunity comes up. IMO keep the Getrag, not the stealth tranny. Getrags were made for serious power, and it would take too much fabrication to put a stealth tranny in.