418 Stroker options....
Here's the thing... You're working to beat a certain car. You say it's a 700hp street rod. What has that car run at the track? (talking hp numbers is irrelevant here) You will not reach a 600hp goal with the budget you have. It would be a challenge to reach 500 with that budget. It's doable - but only just. My point is, you need a realistic goal. Whether that be a blown engine, or a 9 second ride, or an engine for $5K - before you formulate the plans.