Thanks for the replies...

I ran it with 12 x NiMH, since I don't have lipos for it yet. I've heard about the Zippys, but I'm also looking for some used 2s packs to pair up. The speed calc gave between 29.5 and 33 MPH, depending on the exact battery specs I put in. RC8E has 4.30:1 ratio diffs, and 46T spur.