PLEASE HELP.... U Joint Problem !!!! Please I wanna Drive my car:)

Okay Guys so Her we Go I bought a 1967 Valiant Signet With a Fresh 360 and a 904 Trans. The car had the Wrong u joints in it and the caps were all coming off cause the Original owner was a smuck so each ujoint only had three clips in them cause the u joint was to long. So I have Baught 2 diffrent sets of you joints from napa and there all just to long and I cant get the last clip in. I have Tried Napa part 316, 315 they said they dont have anything smaller then that. I dont Know what to do were to look or what I need. I just bought this car and im dying to drive it Please if you have any info please let me know.
You know-maybe you should take it to someone that has a clue about what will work and what will not.If this is just ONE problem it may be alright to fix just one.But if this is just one of many fixes like this-do you really want to rip on it?????