I ran my timing advanced for a few years now, in addition to a higher compression head, and MSD enhancer.
simple rules...
91 or better fuel ( I have ran 87, but never any WOT when im running that)
make sure your jetting is pretty close ( not lean)
make sure your cooling system is working well
I can run WOT for 60 seconds or so with 91 octane fuel, and it will gradually begin to loose some RPMS, I take this as it heating up and slowing down ( from friction) that has happened at least 2 times in the last few years that I can remember..
No damage engine is intact, and running very strong for what it is.
you might get lots of time on it advanced ( I certainly have)
or it might blow to tell the first time you run it WOT, its all a gamble, only you can decide if its worth the risk.