The pro stock motors use Nicaseal , liners in them, and it’s a very expensive process , about $4000 to a block that starts out at $4000 and needs $4000 in work . The reason is ring seal, Ring seal is power, and the straighter you can make and keep the bores, the lighter your ring package and keep seal. A Cummins block is extremely hard and according to Ray harder and better then the DRCEIII Chevy pro stock block, which is cast by Caterpillar .Burner said:I wonder if anyone has ever sleved one? If they had, could they Nickel the sleve as well?