All coordanates are referenced from the original porsche jig holes located on the oil pan rail.  Because of this we are able to correct the cylinder bore centerline and relocate the cylinder head dowels in there propper location. If one so desires they may give us special dimentions to offset the cylinders or even just the head dowel pins.  This is particularly helpfull as a means of changing the effective rod stroke ratio for better cylinder filling.  After the sleeves are installed we ca machine the top of the sleeves to provide a customer specified sleeve protrusion for extra head gasket crush. Our "O" ring fixture (from BHJ Products) makes it posible to provide any "O" ring reciever grove combination that the customer specifies.  We feel our program is the best offered to the profesional engine builder.