I have been giving it hell without a power adder or high stall converter and it is doing ok, Fluid looks fine but next year I expect to have fluid changed and beat the hell out of it yet again. 500 hp is ok so far as I have heard.
Just keep an eye on it.
How about HotrodHarry's car? He has the stock auto tranny in his car, & still retains the stock torque converter, and run's 10s. Though, his car is not abused on the street, and is low miled....I suppose driving it sparingly helps with that?