By sub frame I imagine you mean the actual frame? No.....full frame. If you mean wood in the floor between the seat base and the firewall...Yes. Mine was floppy as heck when I got it. I got rid of it in favor of a steel floor. I'm sure they were fine in theyre factory form and probably would last better on todays roads....and we arent going to abuse them on the dirt roads they were driven on back in the day. I live in a rural part of Arkansas. You know....dirt roads are getting scarcer (is that a word... ) today.

Dave G