No, I think 5000Mah is a good size to run in the savage.
http://www.rc-monster.com/forum/showthread.php?t=8289
This is running 5 cell Apogee 5800Mah. So I htink 500Mah is pretty good.
If you want longer run times, the best thing to do it get a lighter truck, like revo, or go even lighter bugggy.
Also check out this site for Lipo's
http://home.comcast.net/~truerc/read...eady_packs.htm