Chevrolet Truck Shop Manual CAB sec.1-1
A UNISTEEL cab , the most durable type of all automotive body structures ,is used. In this UNISTEEL cab the four major panels ( the cowl,the back,the top,and the floor), with numerous reinforcing panels and braces, are all welded into one permanently rigid, integral unit .
Not wanting to win , just stating the facts ....
I agree! So I will, from this day forward, get off the road when I see an AD on the road, assuming that 9 out of 10 of them are customized and likely missing this seat frame, integral to the structural integrity of the cab, and without it, the compromised cab will likely fly into pieces at any moment. Thank you for your insight.