Since this radiator is only temporary and you don't want to modify your original trans lines...
I might consider running a remote cooler and not use the cooler in the rad. The original lines might have enough "flex" that you can get a hose on the end and still clear the lower rad tank. Mount the new cooler in front of the rad for now.
Good advice...Only other real option would be to see if advance auto,autozone, etc.. Has a fitting in their inventory for the correct bridge between the rad and the line...So much for the "direct fit"...
