It is cheaper and easier to buy an Eagle stroker crank for a 409. You can get it in 3.76 and 4.0 strokes. Ready to drop in. You can use a 6.135 rod with this combo as well as the 6.385 and longer rods if you like with off the shelf Ross pistons. A small amount of clearancing was needed for my 4 inch arm in my 09 with H beam rods.