I am looking for some split loom corrugated tubing that is a minimum
of 2.5" in diameter.

I searched far and wide, with the largest size available being 1.5"
diameter.  Many of the corrugated tubing manufacturers had awkward web
sites that didn't list their complete product lines.

My suggestion would be to use the search terms
"corrugated tubing" manufacturer 
to pull up some names, then call or email some of the more promising
ones.

historybuff

I called them all.  That's why I posted the request.  I can't find this anywhere.

I found that for a 2.5" diameter, the more appropriate search term is
"pipe" rather than "tubing", because you are more in the category of
corrugated flexible drainage tubes (which I did find at 3" diameter). 
The split loom is a problem, but depending on how much of this you are
looking for, could you consider finding someone with a table saw to
slice it for you?
The applications most like what you were looking for were for cars and
vacuum cleaners, and so of course were not split.  There were some
listings for this type of product by companies in India.
I wish I could have found it for you!

historybuff