For those of you that did your own tranny rebuilds, did you flush the cooler lines before you reinstalled the transmission? I was looking in a past Dieselpower magazine and Mike L's shop used "kooler kleen" on a trans swap that they did.

Where can I get some?

I would highly suggest flushing the cooler.
Most parts stores should carry it. If you have trouble getting your hands on some let me know.

Thank you.