You can by those retaining clips in bulk from most trans suppliers, dorman, help section of auto-parts stores, etc...
Many of the rebuild kits include them as well.

 

Thanks for the response vorteciroc. Think I'd be fine without the caps then? I see them online but would put me out at least a few more days, maybe even a week or more. Would like to move forward but don't wanna do anything dumb. Missing my 700r4 with the flared lines and threaded fittings right now, lol.

The clips themselves are new and made under the Napa Balkamp name I believe, i think they are ever so slightly bent differently, mainly the two raw ends where they curl outwards. Also the U part in the middle seems a little deeper. I think that's what's keeping the cap from popping over them. Posted a pic a couple replies up. The blue ones are the new ones.

 

I've seen instances where people didn't use those caps, and the lines popped out.

I've also seen instances where people didn't use them, and they never had a problem.

But I've NEVER seen a line come out that had the cap on it. I'd use the caps.

 

I personally have never had a line come out due to not using the plastic covers...

However as dixiebandit69 stated... people have had the lines come out.

I do not feel this is due to the lack of the plastic cover.
But more of the retaining clip not being installed completely or having been damaged.

Also a BIG improvement for any vehicle with a THM700-R4; would be to replace the original 5/16" cooler lines with 3/8" lines.

 

Ok I found some different clips (really the same thing) and this time i installed the clip first and then pushed the line in.

It seems like the clips spread a tiny bit when installing over the fitting. If i started the plastic cap over the top of the clip first then pushed it the rest of the way on it would snap right on. I think this is correct.