Good luck with the engine, here is a good comparison for you to start from. This article is from Muscle Mustangs and Fast Fords and details an otherwise stock 351 Windsor stroker also with AFR 205 heads that got 537hp. It is "only" stroked to 392 and was only 9.5:1 compression. You are going to be running a few more cubes and higher compression, so I'd say to expect
at least these numbers. Hope that helps give you a baseline. If not, keep tuning it until you do or something went wrong. Frankly, I'd expect whatever Keith and Brent said to expect - you have two of the best engine builders in the country chiming in.
http://www.airflowresearch.com/artic...e004/A4-P1.htm