I am running that same setup on my Duster (HyFire box with stock dizzy) and it's worked great for about seven years now. Those things make a fat spark, gotta make sure your plug wire ends are put on right or that **** will arc and numb up your whole arm if you happen to touch one while it's running.
So a "sorta" update here, I went to this amazingly badass humongous racing/performance parts warehouse only a few miles from me (:D:D) and they can get a new harmonic damper for only $150. I was under the impression that SFI-approved dampers were a good idea on basically any hi-po engine but the guy behind the counter said they're really only necessary on super-high-winding engines (8000+ RPM); this 440 will probably only ever hit 5500 and only hang there for a split second at that. Also found out they carry Brad Penn oils for only $7 a quart which is the same I pay for Valvoline VR1 (for zinc) around here. I'll probably buy a case in the near future I'm sure it's at least a "cut above" the regular brands you get at Wally World etc.