The "quick and dirty" way to check compatibility of a turbo for a different engine is to look at:
displacement x RPM for peak HP x (15 +boost pressure)
The value should be approximately the same on the new engine as on the old. Even this does not guarantee that the turbo will work well in its new home. If it's too large, you get into the wastegate too often and too quickly. If it's too small you get turbo lag.
Looking at your application:
For the PSD:
444 x 3000 x (15 + 16) = 41,292,000
For a 300 assuming 10 PSI and 4000 RPM peak:
300 x 4000 x (15 + 10) = 30,000,000
So unless you're willing to boost your 300 by a lot more and/or spin it way faster, the PSD turbo seems too big. It might work, but not very well. There is also the fact that it is non-wastegated, which could be a problem on a somewhat more fragile gasoline engine.