The 7 bolt flanges you use for a Z31 turbo, despite what appears to be simply the addition of 2 studs onto the 5 bolt, is not the case. Only 2 holes line up, the others are all of by a decent amount. So, don't be stupid like me and get your new turbo with te 5 bolt back thinking AW YEAH DUDE, IT'LL LINE UP FINE when upgrading from the Z31 turbo.
That is all.
P.S. If anyone wants to buy a 7 bolt flange for a Z31 turbo, let me know, i'll try and get it cut off in one piece ^-^
