I am running a 19.5" flex fan (non-clutch). The fan has the stock 8" pulley on it. I read about folks putting smaller pulleys on the fan so that the fan turns faster which would help with a standard fixed blade fan. But I dont think a smaller pulley would help with a flex fan as the blades are designed to flatten out at higher speed to take load off the engine. So turning a flex fan faster just flattens the blades out right?
I thought I had all the filler panels in place but now I am not so sure. I have the two top panels in place as well as the big one piece bottom panel. I dont honestly know if I have the other fillers that you mention (400-X, etc.). I was hoping to find a correct 68 400 at the car show on saturday so I could take pictures of the engine bay for comparison but mine was only 1 of 2 FGFs there. The other car was a 69 and the owner didnt open the hood. Pretty amazing that there were only 2 FGFs in a 400+ car show! I will dig through my service manual tonight to see if I am missing any fillers. It wouldnt suprise me to find that I am missing some of them.
My heat issue is definitely at speed. The temp came down into the 205-210deg range within a few minutes of getting off the highway on sat afternoon and eventually dropped to about 200 sitting in the driveway in the shade.
Good info on the aluminum rad. Thanks! I am glad I didnt pull the trigger and drop $400 bucks on that al rad! I like the stock look better too.
FirebirdMike, You are talking a bit beyond my current mechanical abilities. I dont know the answers to your questions but they are on my list to checkout!