I have a few LV.100 (Uber Legendaries) a few Lucky Eggs and about 12 pokemon I want to get to Lv.100 ranging from early 70-mid 60 to early-mid 30.

I was wondering if there was any fast aways to level them up post Kanto Badges.

The most reliable strategy, I find, is giving the Pokemon a Lucky Egg if their level is not very high and running through the Elite 4 over and over. Once they can fend for themselves, just give them a Lucky Egg and have them go through by themselves. If you have another Pokemon Game, I would suggest having them traded over to that and doing this process, since Pokemon received in trades will level up faster.

Another way to get slightly more out of Kazam`s method is to alternate the Elite Four with battles against Red, and Gym Leader re-matches. I called up every Gym Leader at their specific re-match time until all of them were at the dojo, then, when I want to fight one, I`ll set the game to near their re-match time, defeat them, then call them back, giving me an essentially infinite number of battles against them.

Anyway, Red`s Pokemon are in the 80s, and Blue`s Pokemon in his re-match are the highest in the game besides Red, followed by Lance. So I`d say battle Red first, then Blue, then run through the Elite Four, then battle Red again, then Blue, etc.

Cool, thanks you guys.