Obviously on a Blown alcohol car this doesn't apply but my first thought whenever this is brought up is that often times 10 pounds of inner fenderwell strength from a monocoque frame (which a mopar unibody essentially is) can easily be worth 30 pounds of tube steel in terms of structural rigidity, beaming (as when your front wheels are in the air) and torsional strength.

Review some of those great old youtube vids of the late 50's/early 60's Crysler Unibody frame design and the Herb Adams Chassis Engineering book and some may rethink the hacking many people do on A/B/E bodies....particularly regarding flex in the heavy cowl area. sometimes (and obviously not in all cases) a little strategic reinforcement (gusseting or tubular cross bracing) of the unibody can be stronger AND LIGHTER than completely reengineering your chassis.

The biggest impediment of the unibody inner fenders tends to be the limits it puts on header radius and diameters as well as between round engine access. but those fenderwells also form a lightweight and rigid 'box' that supports the engine and suspension from the main structural bulkhead which on a Mopar is the firewall.

I remember in 74 Jenkins/SRD built a semi monocoque (tube steel and structural sheet aluminum ) framed pro stock Vega (Grumpy's toy X1 I think) with McPherson struts and structurally braced aluminum inner fenderwells that was super light for its time.