[blykins]

For a street engine, I would highly advise against having an engine that makes horsepower at 7000 rpm. These engines are not modern fuel injected pieces with variable cam timing. If you cam an engine to make horsepower at 7000, you will be extremely disappointed at 1500 rpm.

With either the 302 or the 331/347, you can use an AFR 185cc head. It will be a little soggy down low with the 302, but it will be manageable.

The camshaft will dictate where the power peaks and what the hp/torque curves look like. If you are set on a higher revving engine, I would most certainly look at a much lower rearend ratio, like a 3.73 or a 4.10. Durations at .050" of the mid 220's will get you a 5500-6000 peak, which would allow you to shift at 6500. To peak at 7000 rpm with a 331/347, you will need to be in the high 230's, low 240's at .050" duration.

I don't like many off the shelf cams for the small blocks and FE's. The lobes can be very aggressive and generally follow the same 6 degree intake/exhaust duration split as is popular with the SBC crowd. These are all universal camshafts and don't work optimally for every engine family. You can actually lose horsepower by using some of the aggressive cams, such as the XE or XFI series, plus some of them can be pretty noisy.

A 425-450 hp 331/347 would be more indicative of a "performance" street engine. To hit 500 hp and 7000 rpm would require a lot more specialized parts and a lot more detail/skill by the builder.