Cage tube size?

[jjump59]

Working off an old rule book, chassis guy is going to order tube and don?t want to get wrong stuff.  1 5/8 .095 still good?

[jacksoni]

For Moly. Mild steel is 0.120. More is better........

[Stainless1]

And mild steel is the preferred material... Weight is your friend at Bonneville... up to the point that you have to much to accelerate it... your frame is not going to cause that. 
"if the wheels slip ad weight... if they don't add horsepower"
If you are not dealing with a space problem, you might want to consider 1 3/4 x .125, it is more common that 1 5/8.