Bringing up a old thread (I know..). I thought I'd leave my thoughts on coolant. I tried the Havoline ECL Orange Coolant, while it cools way better, it eats seals like mad, don't try it... Also bummed my water pump out the first week I had it in the system...
Prestone yellow antifreeze (I think it was ELC) doesn't eat seals but doesn't cool very well IMO.
NAPA's standard green antifreeze (non-ELC) with Bitterant is my choice, cools well, and doesn't eat seals, then I add NAPAs anti-rust compound and call it a day. After 2 yrs, check it with anti-freeze tester, add LiquidKool and rust inhibitor to the system, and call it good for another year.