out the door turbocharging would cost somewhere around $4,000. for your goals (~450 wheel horse) you can do with a supercharger for cheaper ($3,000), or go with spray. At this level though you'd need an aftermarket block that can reliably handle that power. I would suggest going to a 408 stroked from a 351W, a good set of heads, plus the power adder would get you easily there, and reliably. Don't expect to just pay 10 grand and have a complete ready to burn tubber car. in addition to the motor alone ($5000), you'd need a trans built for that power ($2000) plus a new axle ($2000), so you have 9 grand in the drivetrain alone! you need to get planning before you start wrenching and find where ALL the dollars are going to go and whether or not you are willing to commit.