RE: how fast is a stock FG?
Gearing will determine your top end, MT's come with 16/48 gearing, you can go and get 18/46 (waiting for mine to arrive now) for more top end, I'm not familiar with 2 speed ratios - check out the link in my prev post for more info. Exhausts make HEAPS of difference in power, which will get you to top speed quicker.
People reckon about 40mph top out of the FG MT, with 2 speed maybe 50 -55mph, try doing a search - there's heaps of threads on it like [link=http://www.rcuniverse.com/forum/searchpro.asp?phrase=fg+top+speed&fuzzyMatch=on&author=&forumid=234&topicreply=combined&message=both&timeframe=%3E&timefilter=0&language=single&top=500&criteria=AND&minRank=0&sortMethod=d&submitbutton=+OK+]THESE[/link]