Once the proportionong valve is adjusted for the particular application and such, it works in ALL stops, not just a panic stop.
The issue with the power brake booster is that all factory installations had a dual-diaphram booster, which is longer than the normal power brake vacuum booster. With two diaphrams for the intake manifold vacuum to apply boost with, as disc brakes require additional brake fluid line pressure to stop the car, the pedal pressure input can still meet the USA FMVSS pedal pressure regulations (max pedal pressure to stop the car at a particular decel rate). The dual-diaphram booster was also used on power disc/drum B-body cars, too. Has nothing to do with the weight of the car, just that disc brakes require more line pressure to stop the car than drum brakes (as you now have) do. Some 3000lb and under cars are light enough that a power assist is not really needed for their disc brake set-ups (although some have had a power booster on them).
I suggest you contact Wilwood Customer Assistance and get their orientation on their booster recommendations. BEFORE you got involved in a swap that you suddenly find that you need additional parts to make it work. Just to be safe.
On the "slab" C-bodies, using a larger diamter booster is not a bolt-in situation. After the re-design for the Fuselage cars, then a larger diamter single-diaphram booster was used for all power brake systems. The issue is that a certain amount of diaphram area is needed to generate the greater boost needed for the use of disc brakes with similar pedal pressures (which the driver sees and feels).
In prior threads, some have stated that they got by just fine with their normal power drum brake booster. But I also suspect that IF Chrysler had deemed that to have been "good enough", they would have done similar. Better to be "safe" rather than "otherwise", to me. Which, to me, that means that for best results, an OEM design-components should be replicated when possible OR if they can be improved upon by selected aftermarket items OR, as one upgrade website promotes, using OEM replacement items from local auto aupply sources (which you might not have ready access to, respectfully given your location).
One "generational" issue I have is that I remember when Wilwood started selling front disc brake kits for drag race cars, along with a related master cylinder. Given that their focus was drag racing, "weight" was an issue in their designs (meaning physical "light weight"), meaning that they were weight-saving over similar OEM designs, notably so, by comparison. Looking at their current kit offerings, I can't help wondering about the robustness of their items when compared to OEM designs. Not that the Wilwood items are bad, just that they seem a bit "light" to me. No more, no less.
One "plus" for the Wilwood items could be their demonstrated longevity in the business and good availability (I suspect) of replacement parts when needed. Given the suspected future availability of drum brake system parts.
Pluses and otherwise, to me. Maybe I'm just getting a bit more conservative in my advancing age?
Enjoy!
CBODY67