Any pics of a bare 1975 duster Firewall ?

This is a 74 Dart non ac:

What I am trying to see is behind the dash, behind, and above the passenger side heater/air box, the cowl attached to the inside of the firewall seems much more shallow than in the earlier 69-70 cars. I'm trying to decide whether to remove the heater box, cut a hole though the cowl, plate the reverse side of the firewall, than patch it up, and do a shock tower reinforcement on the engine side.