Stock up pipes- what are they made of?

[dmaxvaz]

I was wondering what the stock up pipes are made of? Mild steel, stainless? 409ss, 321ss ? Just curious

 

[Turbo Buick 6]

Ferritic SS (4** series) I belive they are 409, a staibized grade

http://www.duramaxdiesels.com/forum/showthread.php?t=9885

Post 4 should help you