shackles ?

I'd suggest you get ones that are rated the same as or just a little higher then your weakest link because any bigger would be a waste. And another set smaller just in case holes are smaller. Usually D shackles have a wider opening then bow shackles which can be an advantage.

 

Hey 281, nothing wrong with over kill in this biz.
You'll get the most use out of the 15k WLL shackles. They seem to be deep enough to fit most tie down holes,
But every once and awhile you'll get those deep set holes with the 2" thick metal and the 20k shackles are the only thing that'll fit. I have 4 of them and smile every time I have to pull'em out.
Sure beats pulling the kotter pins, running chain thru re-pinning, than again at the other end.
That's just to much extra work for me.