You don't want to buy those 1.6 rockers anyways. There's a marked quality difference between the 1.5 set with the steel hold downs (this set is sold by other vendors like PRW) and the 1.6 with aluminum.s
The 1.5 steel hold down set has bronze bushings and the machine work on the rockers and hardware was decently done. They were a little gritty, but after a cleaning all the threads checked out good and the rockers fit well on the shafts.
The 1.6 aluminum set are also bushed, but using iron/steel bushings. They weren't reamed as well and didn't fit the included shafts properly. The threads in the arms were poorly done and needed chasing, and the oiling holes in the adjusters themselves were drilled off center on a few parts.
Same factory, but likely made to different quality requirements and SM buys the excess stock on the higher quality parts. PRW sells those same 1.5 rockers for $400+.
