Jeff Creech knows the ropes. He's a big proponent of finding MBT on the dyno and then knocking a few degrees off of that so the engine lives a good long life. I've met him a couple times, talked to him quite a lot online, been on his dyno once, and he hosted a Fanglers mini-meet for me back in '05 or so. Not a n00b, wreckless, or dumb.
I've really got minimal Chebby experience to know anything about required timing. I believe some of those motors like a lot of timing, although you are knock limited by your fuel. I recall old man Hendren in Rutherfordton builds some SB2 based 350s that make 800 whp at 28-30 degrees advance on VP 118, IIRC it's a 67-70mm compressor limited class they compete in. He told me a bit about them when I was on his dyno some years back, so my facts and figures could be a little off.