I've had a 509 in my 383 for 16 yrs or so. I was very happy with it. When I first put it in I would race some with it but has been street/road with the very rare street drags(Shhhhhhhh!!!!) I recently flattened a lobe and was going to replace it with another until I saw the price!
Looking at Comp's equivalents. They are much more affordable and spec'd pretty much the same. I want to keep the lope of the 509.