skirecs,
I'll be looking around too but if you do find ones that will fit please notify me. Thanks.
Psychotic lego man,
Like what skirecs said, if you drive around at half or two-thirds of the power you should get about 15 minutes of run time. I ran three tanks yesterday and it lasted me an hour. You will need a .12 or .15 engine to legally race or if your track has one you could just race in the outlaw class. I know putting aluminum on is good because it's strong but if you were racing wouldn't you want to put something lighter?