Or maybe your can just needs to be slid back a little toward the box. Mine never hit the firewall until lifted the cab and put her back down. Rubbed firewall. Loosened cab bolts and moved her back a little and no more hitting.
Hmmm. That's the first I've heard that. I'll give that a shot.. I know this is probably going to sound stupid but I don't have a lift to pick up some of the cab weight so is there another way to scoot the cab back?