Wilwood Disc on a 73 Challenger

Just purchased a 73 challenger, love it but it will not lock up the 4 disc in a panic.
I have a 20# electric vacuum pump and a new booster. Brakes work good around town with normal stopping. Petal becomes very hard in a panic and feels like wet drums.
Wilwood tells me hyd is the only option but I am having a hard time swallowing this.

Any ideas?
Author: Steinman