Just to chime back in again, I can't point to the fan being 50/50 in the shroud as the magic bullet in cooling temps. I made the change when I rebuilt the engine. So I started with a clean and de-flashed block, did the water pump plate mod, have all the radiator side fillers, x panels and lower filler panel, clean 3 row radiator. What I will say is that after reading a ton about overheating problems and the fixes, I did all I could to not skip any steps. This will be my second summer with this set up on my 68 vert with a 461 and a/c. So far I have not seen it get above 185, even here in Phoenix.