How much hp is too much for my axles and axle u-joints?

[Big-Blue]

So my front end is carrying a 1971 Dana 44. I am rebuilding everything from the pumpkin out, ball joints, bearings, etc. I am dropping a 504 hp 383 in it and started to question if that may be a bit much for the stock axles and u-joints at the axles.

I won't be doing any rock crawling, just hauling and an occasional mud run.

I am in no hurry and I have it all apart so should I upgrade to some after market axles and joints? Is it worth the extra cash?