i hear that borer bugs like BL so removing the sapwood and coating the stave with bugspray/bug repellent. and then a sealant on the side you removed the sapwood from and on the ends. This should prevent checking and cracking. Hopefully someone else will either confirm this method or give you an easier one. Those are some big logs btw, you would probably want to split them into quarters or sixths maybe eights, just make sure you have room for a bow in each stave. Not sure if the sapwood is any good either, as a said, hopefully someone will comment with more info.