Stock 302 shortblock will make 375 or close to it, but you will need a good H/C/I package with a fuel system that can support that... It will cost you some cash to do so... it will be a lot easier to built a 331 or a 347 stroker and get to that power level...
I agree... those number are not high... Your number seem low... it all depends on the tune, cam, flow of the heads, blower specs, machine work on the block... But i dont think his numbers are high...