You can see anywhere from 300-450rwhp, depending on a few things:
- Budget
- Heads
- Camshaft
- Intake
- Supporting products (MAF, TB, Exhaust, etc.)
- Powerband
- Goal of engine
- Compression
- Daily driver, street car, or track car
- State of tune
- Accessories driven by crank
- Transmission used
- Overall knowledge
- Knowing the right people
and the list goes on...
Most is usually determined by the buyer's budget.
Do not let anyone tell you that a 320 or a 380 rwhp 347 or 331 is horrible. Because often the final output is based upon any combination of the list above...
Good Luck!