Big bore YZ

I'm sure its been covered but instead of dragging out multiple threads from the grave, I'll ask again. Best option for a big bore YZ? GYTR/Athena 300 bolt on vs Eric Gorr vs any others? I'm a bit confused, some places I've read that Gorr only goes up to 265/285(can't remember exactly) with stock cylinder. I'm a 300 guy through and through. Some people believe that there is not a great deal of difference between a 250 but it is night and day. Im not wanting only more power but more specifically a different spread. Huge bottom end, flat transition to mid and able to run with a 450 when twisted to the stops. I know it's possible, my highly tuned 300WR has this spread.