Currently ,there are more authorized manufacture to produce the cummine engine parts like CCEC (mainly for the M11 ,NTA855 ,K19 ,K38 ,K50) ,DCEC (Mainly for the 4B ,6B ,6C ,6L ,ISLe,ISZe,ISDe),SFG(Fleetguard Filters) and Holset turbochargers.we sincerely recommend those china made series cummins engine parts for you ,as the price is much more competitive for the original ones .Especially the fleetguard filter and holset turbocharger ,they are not just focus on the cummins engine but other brand engine like VOLVO ,SCANIA ,Komatsu ,Man and ect .and most of the filters of Donaldson ,Man ,Cat,here we can find the subsitituted fleetguard filters for you to meet your client`s requirement of reducing the cost .