universal joint fitment issue

Nope, There is a machined groove on the inside of the cap that the snap c ring clips on the cap and a machined edge on the inside of the pinion to keep it from shifting around. There is no way I can get both rings on and have it fit.... The napa part in Canada was UJ347 and the US part number is nuj240-0369

Any one help?

Please!
I have also found some aftermarket clips too thick to fit correctly, & as mentioned some pinion yokes have retaining tabs & do not need the clips,
and may not be machined square to accept them.....................