A518/46rh and A500/42rh lock up question

a500 will it handle hp?
Hey guys
Thanks for your input. I am at a crossroads on which trans to buy. I would prefer the A500 as it will give me the overdrive the same as the a518 and is easier to fit. However I will eventually chase hp and am worried about its strength. I currently have a a518 in my other car which has 420 hp at the wheels and the a518 seems to be fine. I guess it would have around 550hp or more at the flywheel.
Will the a500 be able to take this power as well? Or will it struggle.