[Rimrock]

To keep initial purchase cost of the machines relative low, the chineese generally uses soft steels, brass or aluminum combined with as few gaskets as possible in their valves and pumps. The service life will naturally be less than the more expencive brands made of harder materails, closer tolerances and with proper gaskets all around. I've upgraded a couple of 4200xl, and some other low cost machines, all with Premcaon hydraulics that is at the high end of the scale. All hardened valve blocks and hydraulic pumps of industrial grade, not toy grade. The valves have a more realistic smooth feel to them then the low grade valves which often feels more 'on/off'. (for smaller excavators/wheel loaders there are some less expencive good quality options from Magom and Lesu, but for the relative large machines as 360L and 4200xl I only go for Premacon)
There is no particular packages for upgrades, one have to pick the components one by one. I recommend their largest pump, 1200 ml. In addition one find the pressure valve, filter, 5 way block + servoes and brackets. The chineese uses a hard grade of hoses in their machines which I have experienced can be quite a pain to connect to the fittings. One can concider also to get some of the Premacon 4mm hoses which are of a softer and more user friendly grade, put still strong enough. Adviceable to use 6mm hose on the intake line tank to pumpe for best flow. One can re-use most of the existing fittings, might need some more but it all depends how one install the equipment. Can be handy to get some T-connections (need at least one for the pressure valve,optional one for manometer), endplugs, new gaskets for the existing fittings (Premacon gaskets are thicker and softer than the thinner chineese gaskets, otherwise the fittings rc4wd vs premacon are the same) In additon Loctite 542 is highly advised to put on the threads of all fittings. Oil grade 22 is used, same as rc4wd.
(NB! One might come over a pump from Magom that looks similar as Premacon, at at lower cost. The pump unit it self is the same but the motor and gearing is not proper designed at the Magom pump causing overheating problems in my experience)