I have a 390 in mine and although I've never had it dyno'd, it has plenty of power. If I had to guess the hp, I'd say in the neighborhood of 400 to 450 (?).
Mine is .030 over but not stroked. I am running approx. 9.7:1 compression with aluminum heads, 296° dur. w/.572" lift on the cam, performer rpm manifold, holley 770, dove aluminum roller rockers, flat top pistons, msd ignition/pro billet distributor, double roller timing chain, etc, etc.
This setup is very streetable but still quite capable of quickly melting the tread off the tires when desired. Now of course, you don't get the same bragging rights that you get with the 427 SO, but for 1/2 the cost, I can deal with that.
Gene