Backyard they are awesome, dont get that thats too much money they are just trying to sell you the stock 1 I have never heard of a factory mod, and I drive for them. I could be wrong but I doubt it. PM me and I can get you to the US sourse. About my idle adjustment Q earlier I was only asking because I always ran the 8 and 7.5 with no need to adjust the idle screw, but going to the 6.5 I was just wondering never used such a small restricter. I was just picking my brain thanks.