Chrysler built literally millions of cars with swaybars, but never used LCA stiffeners, so they aren't some kind of "you gotta have both" item. Stretch's car is about as heavy as an A-body got, giving up very few pounds to a V8 car. It needed the swaybar because the car leaned so badly in normal everyday driving, not canyon carving. With me in the car, the RF tire would rub the fenderwell on LH turns from a dead stop. It really should've had one from the factory. It's not a "corners on rails" thing, it's a "can we not rub the tire on low-speed turns?" problem.
I bought the exact-same swaybar for my '68 Valiant, which is also a slant six manual, but without AC. I have no intention of wasting time, money, or effort to make it a corner-burner. I have other cars for that nonsense. I just want it to feel like it won't roll over in low-speed turns... same as Stretch. Since neither car will be driven hard and with both having optimum fuel economy as a primary goal, adding useless weight is a move in the wrong direction. The only reason His Elasticity even bothered with the four-speed was to get better fuel economy. Yeah, it'll be gutsier off the line but that swap was not done as a performance upgrade because it's not a performance car. Neither speed nor handling are not concerns, so long as neither is frighteningly bad.