Ok measure at edge , blocks some times run up hill or down IF you need ZERO deck max comp(square deck) front to rear
you may have to shim block in mill before facing deck, You still clock block in on mill (after you know, up or down at 1 end on bench) it maybe flat on sump rail and deck runs up or down hill or Rods maybe out or tunnel or a combo of all
Mark chapman (chapman brothers racing engines perth au)