Hello, on the 29 Tudor radius ball socket. I understand the parts needed for the original setup. My friend has the lower socket, springs, bushings castle nuts and cotter keys, also has a new spacer. He seems to be missing the upper cap, the one with the hole. He appears to have two lower caps. Question is can he turn one of the lower caps over and use it as an upper cap? Is the only difference that the upper cap has a hole in it? I know we can order a new upper cap but seems the vendors only sell the complete original setup and not the upper cap separately. Thanks.