Are you using the 1/2" foam between the radiator and the H/E to keep them from rubbing? I'm using the Super Cooler from DJ, He uses welded on tabs to mount the super cooler to the Factory H/E mounts and you really don't the the foam or the Zip-Ties. I did add a 1" X 1" strip on each corner just to make sure no rubbing occurred I'm getting plenty of air from the sides and top so My temps. haven't changed. Living in New Orleans it gets very hot, today it's 97 F 100% humidity YUCK!!!

I am noticing the fan running maybe 15% more in traffic but it will cool down sufficiently enough cycle on and off. I just had major modifications done and haven't seen much of a difference with additional temps.
I might modify my stock Stat (search on the forum) you drill 4 small holes providing circulation before the stat opens. One last question... What size hoses are you using and how did you isolate the systems.

Cheers and good luck
Collin
the Crazy Cajun