engine swap

I bought a 79cc harbor freight predator engine despite my Dad's warnings that it would never fit in my frame, he was wrong, but only by 3 millimeters (actual figure, I measured)... here's some pics... http://imgur.com/a/MguAc

So yea, my 66cc chinagirl engine breaks like clockwork every 3 weeks or so, never the same thing twice, but always something new to fix, and I'm sick of it. Plus it's really underpowered and has no hill climbing power and (at least in my opinion) pretty mediocre speed. So, I want to swap it out...