How much weight gain from adding a Dana and roll cage.

I have a rough estimate of my cage and frame weight. I came up with 262 pounds.
That's a 14 point cage with a dash bar and rocker bars.
Cage & frame materials consist of .120 wall 2 by 3 and 2 by 4.
.134 wall 1-5/8 mild steel.
6 by 6 .125 plates × 10