I didn't separate the cooling circuits because I didn't bleed the air out of the H/E by running the pump with an auxiliary battery. I pinched the return hose with needle nose vice grips and drove around the garage. Today it was in the mid 80's, it never gets cold here so I won't wait too long to do it. I took the car out on a long drive around with the air conditioner on and I didn't notice less cooling or the engine running hotter than normal. I need to drive a bit more before giving a full review. Like I said before, so far I'm impressed. I'll try to get another dyno soon to document any gains. My last dyno was only 2 weeks ago. Oh, free mods are my favorites!

Les