Moped Army

So my friend and I are in the process of kitting our e50's. He had a 70cc Athena kit that failed on him because the brass bushing on the stock crank gave out and broke the crank. Now he is putting a 74 gilardoni kit on and I am putting the polini 64 kit on. I ordered all new bearings and seals and we both ordered roller bearings for the crank. As he was putting the kit on last night he took out the brass bushing and had to open up where the wrist pin slides through quite a bit in order for the roller bearing and wrist pin to fit. Is this going to weaken the crank enough that it could fail here now instead? I remember reading on a thread that someone said the stock cranks are pretty strong except for that brass bushing, but does taking all that material away in order to put the roller bearing compromise it and is it worth upgrading the crank?