You don't fully understand.
A *.wad file needs to be under about 200mb. A *.wad file above 512mb is impossible.
I think you're confused with the term *.iso or *.wbfs
Note to everyone who wants to contact me:
This account has been abandonned as of February 1st of 2020. Because I cannot share any links to other social media in this signature, I recommend you to Google my username, and some of the top results may help you out. (or search for my GBAtemp signature, which should be helpful enough)
Do not try to send any DMs to me via the EPForums, because I've disabled them.
Also, to any of the mods on this site, do not delete this account.
Regards,
Trash_Bandatcoot