original or stainless firewall

[twillie2460]

I have a 68 sw and I am pretty sure I will have to take the firewall off as it has serveral spot of rust, top and bottom. So if I have to replace this firewall I am thinking about a stainless firwall, I 've see it done before not sure on the specific model of vehichle but have seen it. I am just going to throw this question out there as see where it may take me. How hard would it be to shave the firewall and put a stainless one in. Has anyone seen or done this or even herd of it on these trucks. Thanks for all replies. I will post a pic of the truck as it sits now.