Well I've torn down about 5 12a's and 2 13b's. I got to thinking the 13b coolant seal landings cant take nearly as much abuse as the 12a's. Out of all the 12a's I've taken apart I have never seen a coolant seal landing damage. Well to get to my question why did Mazda change that. I noticed alot of 13b's have this damage.
thanks
-Matt