Tips for removing a stubborn pedal?

So last night, I managed to strip the bolt on my left pedal trying to remove it from the crank arm. I have a good, large, Park Tool pedal wrench and just could not budge the thing.

Any tips for getting that puppy off? My bike box won’t close!

Thanks!
Busted knuckles in New York,

Is’nt the left one reverse threaded? one is the opposite, just a thought.

Thanks for the responses. I think I may have been turning the wrong way. What a jackass.

Thanks again.

check that crank, if you really crank on it, no pun intended, you could have cracked it if you were turning it the wrong way, it would split at the top.