I have installed the underdrive pulley as of yesterday. It was a little bit hard to find on the MACE website. They mentioned somewhere in the page that it would fit the LY7, or, the Commodore VE (Alloytech) which is the equivalent according to someone at MACE. It does not seem clear whether or not it would fit the V6 G8's but I emailed them and confirmed that it would. It fits well, it is torqued to specs and so far it seems to kick harder at 30 when the hammer is dropped. I have other upgrades so I was unable to compare it to bone stock but I am happy with the results. It came with 1 20% underdrive pulley, two idler pulleys, and a poly-V drive belt. It is a little confusing ordering from AU with the money conversions but after it was all said and done I ended up paying 254 U.S. dollars.