I will be getting a sv27 soon an i was woundering what would be the best prop to get for it? I will be running it on 4200 battery pack and all so can you run it with two batterys or not thanks

one more quick ? were do you guys get the extra turn fin and does the trim taps for the v 24 one design work on the sv27.

short answer: x440/3, x642, CF45


Long answer:
http://www.rcuniverse.com/forum/m_4835624/tm.htm

There's more info about props than you will know to ask about

props, turn fins, adjustable tabs, better cooling etc.
http://www.offshoreelectrics.com/about.php