Check this out. www.locknstitch.com Look at the repair section on Cummins model B head repair. It is pretty amazing. They also show a repair to one of the 6BT "53" blocks where they actually cut a section of the block out and stitch in a new section of steel. Look at the stuff they've done to huge compressor cases, steam turbine cases, etc. I bet they can pretty much name their price on the big stuff, the daily downtime costs are a lot of money.