to be honest the z6... ive sported both,z6/b7 mini me and the y7/y8 mini me the z6 pulled hell of alot harder.ive never done the y8/b7 block because the wiring is so much harder.cause from what i hear that you have to run a jumper harness...go with the z6 i have a complete head ill let go for cheap and ill help you

ps timing might be a b****