in my 79 bronco (witch is dura spark) im running a crain hi-6 box and yes i got rid of the duraspark box.......now in my 94 stang im runnind a msd box and a addapter harness and left the factory stuff there.....if the msd box goes bad all i got to do is take the harness out and hook it up the stock way and i can still get home
__________________ 94 gt aode baumannator,pi stallion 3000 stall,transgo,mega bite jrs,3.90 gears,31 spine moser axles,comp exteme,1.7 roller rockers,190 pump,mac cold air,ford 1 5/8 unequals, off road h,flowmaster 2 chamber with stainless tails,msd box,PIH(a9p computer ajustable fan controler),q1a k-member,kenny brown frame ties,driveshaft loop,air pump eliminator kit,bbk 70mm tb,pro-m bullit meter,24#injecters,ported heads&intake,and all the little bolt ons. | 
MSD replaces Duraspark? 
