Hi Marco, nice to meet you here!
Installing them is not as problematic as described, cooling the bushings down, pressing them in position is not a hard work. The case has to be in a good position under the press tool, that's all. The bushings can be secured with a 3mm inbus screw, mounted between the bushing and the case. The bore has to be clearanced, untill you have a distance of 2-3mm from lifter top to highest cam lobe position.
Even if some people don't want to hear it. You can run those lifters with a lot of cams, but they'll run only safe, when the complete valve train is intended to work with these lifters. I know of many failures, mostly when customers run spring rates, that are too high and never needed in a light valve train. Maybe that depends on the sentence, more is even better, but in this case, too hard springs, too heavy materials ( e.g. steel pushrods & retainers) make the advantages of these lifters away. As this lifter is consistantly developed, it's a perfect product, without any competitors in this league of performance gain. This is why it's sold for over 7 years here and it won't be stopped through rumours
! If you want lighter parts, ask us, we can deliver you ceramic valves, if you want to.
I think, you're on the safe side with all the parts I delivered to you. Max knows, how to rework the valve train.