[freebird69]

I've been struggling with high heat at idle for a long time and none of my attempts to solve it have ever been a complete solution.

FYI, I have never had a heat issue while moving at +20mph, only under and especially at idle on days over 75 degrees. I have managed to sneak up on it by changing to an aluminum radiator and NOS water pump with cast impeller but the temp would still climb when sitting at idle. I have a shroud and have tried many different flex and clutch fans but up until recently nothing worked as well as my stock 5-blade flex (assisted by a Spal electric push fan), but even with the Spal running my temp would keep rising.

Two weeks ago I replaced my stock flex with a Derale 17019 6-blade flex and so far it has been keeping the heat under control. I run 2800 rpm at 70mph and on the e-way I was at 180-185 degrees. At idle the highest I went was 200 on an 85 degree day in direct sun and when I engaged the electric fan it went down to 185. The ultimate test was at the Woodward Dream Cruise where I was idling in heavy traffic for long periods of time and never went over 200 degrees.