On 93 pump fuel you should be able to run up to 18psi...maybe even 19psi. The key is flow on the back side, and with the new COMP turbos I am not using you can go with a 1.32 a/r or even the 1.52 a/r turbine housing.
650whp should be attainable, 700whp could be pushing it a bit, and to be honest, the extra 50whp is not worth the risk with a bad batch of fuel. At the end of the day, your tuner will give you whatever he feels comfortable with.
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