Well I've got the full weights in there, probably more than I need! I put a full pound into each front tire and about 1/3 lb into each rear. Maybe that's a bit excessive but it's damn planted now! Rovers are nice, but not very grippy in the garage. Maybe they need to be broken in.
I haven't had a problem with the stock body but the Rovers are a bigger diameter so we'll see. Here's some pics from today-
weights from Cabelas
teardown and buildup. Pics speak for themselves

one of the rear wheels

one side done

one of the front wheels
done