Not to drag this backward a bit, but I think the average v8 enthusiast runs less than 1 hp / cubic inch.
Every guy with a 350 camaro thinks he's running 300 hp and 13 seconds. Most run in the 15's and 16's. Use a calculator and thats around the 200 to 250 hp ball park.
I guess the answer to the query is, whatever you can afford, and think is streetable.
Most people would be very satisfied with 1 hp/cube, if they had a chance to drive such a car.
For the guys who have done better, I'm glad to hear it
