While getting 500hp out of a 350 is very possible, it would be much easier with something like a 383 or 400. Depending on your budget and the intended specifics of the car, weight, transmission, gear ratio etc, there are a number of routes you can take. Since you are familiar with cars, as you know, an engine should be built for the entire package of what its going in.
Where do you want your powerband? Do you want low off-idle performance or do you plan on running a stall and building more for mid-top end power?
Just some food for thought. Once these things are taken care of (and im sure even before that) there are many knowledgable people on here that will give you proven combinations to achieve your goals.
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