I just had new rigging made by Hall Spars.
I got all the measurements from Performance... when compared with my old rigging some seemed right some didn't.
They told me 39" for the bridles and that's what my old ones were so thats what I got for new ones.
I didn't replace my spin pole bridles but I am still using the ones on my midpole that I had on my endpole just with a spectra pigtail (like Todd said) thats a few inches longer. The spectra allows you to adjust for luff tension.