That China turbo is low price as compared to a name brand like Garrett.
Here is one, but is a Garrett. http://www.full-race.com/store/turbos/garrett-gtx-series/garrett-gtx3582r-turbo.html

The turbo you have a link to will not come close to 750 HP on your 250, it is too small.
IIRC, the turbo you have now has a 57 MM compressor housing, the turbo you posted has only a 62.5 MM wheel, it's bigger, but not enough to get 750 HP.

The turbine wheel is too small also on the turbo you have a link to.

That turbo is not enough for you to get to 600 HP either.

"My horsepower goal is in the 400-600hp range"

The HP you are looking for, is that crankshaft HP or at the wheels HP?
I am thinking you are talking about crankshaft HP. Correct?

MBHD

12 port SDS EFI