Installed the S&S 557 after I had maybe 6,000 miles on my '13 TG. Notice a big change in the bottom end performance. Seems to be a whole lot better taking off from a stop. Better low end pull all the way around. Only thing I would have done different is I wouldn't have gotten the "easy start" cam because the '13 has, which I didn't know, compression releases built in already. Causes me some issue staring when the motor is hot. Have been considering pulling the plug on the stock compression releases.
8~\o