Softening the chambers is something that is done usually to nitrous engines to keep from melting pistons. I have never seen it done on a Mopar engine, I have seen the mod on a few Chevy engines. The last one was a big block chevy with raptor heads on a mud racer. Basically they CNC the chamber to give it a taper from the quench to the valves. Reher Morrision did the work.