Well I think you just went little overboard with coparing 8th Gate Gai to Sayian saga goku, but It is not stupid or ridiculous comparison at least which people have done with comparing part 1 or begining of part 2 Naruto to dbz characters.
Well Honestly I am grat fan of both manga: dragon ball and Naruto so I have to admit that 8th Gate Gai is not pushover but dragona ball manga part 2 is really on another level, well I think that Gai could have even problems with 23rd Budokai due to Goku's kamehemaha stated as Moon buster. Now it depens if 8th Gated Gai's attacks have potency of moon buster... well I doubt it, Country buster at the best.
IMo The strongest Opponent Gai would have slim chance to beat would be Raditz , the first villain in dbz and it is very generous to say it.
Anyway, 8th Gated Gai clears almost completly dragon ball manga part 1 expect end of dragon ball Piccolo Jr. and teen Goku.
The thing is 100x power is a MASSIVE multiplier.
If Gai's base power level is even 10...that brings him up to 1000
and I have a feeling his power level is higher than 10
Just because he can't harness the Ki to destroy a planet, doesn't mean his Taijutsu isn't saiyan saga DBZ level
^^ Well that is true, what you stated. I am sure Gai in base is not stronger then 10 by db power scaling, yes he is just as strong as kid Goku nothing more.
In other words 8th Gated Gai is the most Raditz level..., or very close to him