Is ballast legal in stock?

[Larry Boardman <webdoc@javanet.com>]

I know in stock you cannot reduce the weight but is it legal to add
weight?  I am wondering if I can add some secured ballast in the rear of
my car for traction.  In my car it would not hamper acceleration as I
have more than enough power.  The problem is a light rearend.  Just an
idea.  I've seen a few SP cars with ballast on the passenger side to
even the weight distribution.

Larry B
F/S