you can put a late a12 sump on an a15 IF you clearance the sides of the sump where the rod bolts are going to hit it.due to the longer stroke of the a15,the a15 sumps have indents for clearance.the easy way is to line up the rod bolts with the side of the sump,then using a round extension bar from a socket set,usually a 1/2 inch drive,& a hammer,place the bar on the side of the sump where it lines up with the bolts,then hit the bar with the hammer once or twice.this should give enough clearance.the cork gasket is wide enough to cover the little indents.cause it makes a godawful noise when you run the car if you don't.might even post some photos of the a15 sump i've got off the motor at the moment,just by way of illustration.