been there, done that. I converted a thunder tiger eb4 to electric using the leccys from a e-savage/zilla. The buggy was a bit too heavy for it really, had problems with keeping batteries in it too
This is how it looked when I finished the conversion
After testing it ended up like this
its missing the massive fan I had on it too!
It has to be brushless and lipo to work!
http://seanbedford.co.uk/ go on the hyper 7 page, nice one there