Why does Goku say he's SSJ3 form is the strongest in Battle of the Gods?

GT does not exist in original manga where as Battle of the Gods was happened in between the missing events of Chapter 517 and 518(during the climax of Buu Saga), here Goku never reached the SSJ 4.

Edit : never insulted anyone during my answer but man people calling other stupid when they do not know anything, GT is an anime original series supervised by Akira Toriyama (that is the only part where this series belongs with Dragon Ball series) but Akira was unhappy with the way anime studio was handling his story hence left the project in middle. Now his original story ends just after Buu Saga and like I said Battle of Gods took place in between the missing events of Chapter 517 and 518. Dragon Ball series had total of 520 chapters so I don't know when GT happened in that 2 chapters time-frame.

For more information

http://myanimelist.net/manga/42/Dragon_Ball

Read the review of GT here

http://myanimelist.net/anime/225/Dragon_Ball_GT/re...

DBGT is often considered by fans to be non-canon to the DB storyline, but GT is irrelevant as Battle of Gods takes place after the Buu Saga and before the 28th World Tournament where Goku meets Uub.

You guys are all stupid!!!! Don't insult him because the layout is confusing. Dragonball GT is part of the Dragonball series. There's 3.

The first is the original Dragonball series that focuses on Gokus arrival on Earth as a baby and him growing up.

The second is Dragonball Z and the focuses on Gokus adulthood and fights to save the universe.

Dragonball GT is the final and focuses on the last chapter as Goku travels the Universe as a kid.

The movie is between the Z and GT series because they wanted to fill in the gap

that is the moment of dbz because in GT dragonball ends that why they do a restart at the end of z so at that

moment goku was never ssj4 or fiught againt shenron

Dont ever watch Dragonball Z ever again GT was never apart of the Dragonball series your an idiot just how could you not know about this, this is basic information if you dont know that then you should just give up.