Saw this in the Fb group HO Fray Cars and Racing... it was a post by Kenneth C. Stephens. He posted the following:

For those trying to find that little extra something.... 
or those that say “why is this car so loud?, everything is new”......
Just like painting, it’s all in the prep.
Just trying to help a brother out....
What’s in your race car?

When lightening a body or redistributing the weight of the body here's a little trick that might be helpful in determining the thickness of the body and where. Hold the body up to the light and you will see darker areas where the body is thicker and lighter areas where the body is thinner. I apologize for the pic, but it's tough to hold the object and camera steady... :-)

For all you casters out there you know about casting and casting residue. The residue that is left after the resin has cured. Well I have found a way to quickly and easily remove that resin residue without damaging the mold.

For those that might be interested, The secret to the chop is the under side.