Horsepower Estimate?

All I know if I asked builder to build me a run of a mill 400 hp sbm and he asked what was that to me and I'd say Around 10:1, 235° cam, air gap, 1 3/4" headers, 750 and like 225 cfm heads and the builder said that only a 375 hp engine on his dyno, then I'd I want your 375 hp engine then, what I wanted hasn't changed whatever dyno numbers you give it.