You can make bigger power on 91/93, you just need to go up in Turbo size. The crp won't be big enough, you'll need Borg Warner efr or Garrett G Series kit. Again working of the principle of dropping the back pressure and over all cylinder pressure and making everything more efficient.
Also a whipple 5.0l on 91 octane is probably going to be disappointing as well in the Raptor. They make 600 ish hp and low 500s for torque in a non raptor so it'll probably be high for hundreds for torque and mid 500 horsepower with the Raptor drivetrain.
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