No Billet, But I cast cases for the 250 mx engine.
The YZ and CR are the most popular and other than crankseal bores are interchangeable.
My cases are 400.00
New design and heat treatment will be available soon.
I have 1 of tims bottom ends with a cr250 cylinder. Havent run it yet due major procrastination but for being cast in a garage i have zero complaints about the quality. Saw a little inside when i had cylinder off to drill my pulse port and looks awesome.