I used a z6 when i did it. Also if ur b7 smokes any at higher rpms i wouodnt recommend because it will only get worse with it being a mini me.i am stumped on what head gasket to use, am going to put a d16z6 head on my d15b7 lower half. some people say to use a d116zd gasket and others say use the y8... who know which is best