It can still be streetable above 600, 500-600 if done right will sound nearly stock. If he does elect to go with a stock magnum block they are good to right about 600-700. Thats the neighborhood that block failure is a very real risk. I guess you're right, too me i was thinking budget and said streetability. My college budget can't factor in an R3 block.
I went back and reread nothing was stated about what the car will be used for. Is this gonna be a driver, strip car, or street/strip?