On the Cummings six ,each cly. has it's own head and the cly.'s unbolt so you can rebuild it in the chassis of the truck.That explosion took the heads ,cyl.'s and part of the block with it .Those pulling tractors run huge boost and some run nitrous and propane .Basiccally anything they can throw at it .So I'm still trying to figure out why the top part of the motor separated from the lower portion. On those turbo diesel motors, does the block come in 2 pieces that bolt together, or it is 1 solid piece like you find on a gasoline motor???