These lower pulleys are compatible with ATI part numbers 918854 and 918856 for the LSA and LT4 (Camaro/CTS-V only) damper. They are machined from 6061 aluminum and anodized for protection.
The pulleys are available in three sizes:
230mm (9.06″) [LSA 16%/LT4 13%]
240mm (9.45″) [LSA 21%/LT4 18%] IDLER RELO BRACKET REQUIRED FOR LSA
250mm (9.84″) [LSA 26%/LT4 23%] IDLER RELO BRACKET REQUIRED FOR LSA
Note the 9.84 can interfere with the sway bar on extreme suspension geometry events in LT4 ZL1s/CTS-Vs.