I saw several billet aluminum 4 cylinder Chevy race blocks at Joe Deppe's place when I bought the Duggan 12 Port Head casting patterns from him. He said it cost him just $2500 each to have them made. So a 6 cylinder shouldn't be a lot more to have done.
The LSM blocks dont have the same bore spacing as the factory blocks do because they are 4.250" bore. So a longer crankshaft and cylinder head will also have to be made also. Every component in them is custom and has nothing in common with the production 6 cylinder except it has 6 cylinders.
