Speargun, I just read your thread. Nice work. Interesting that you mentioned extra cooling capacity, a coworker and I were geeking out about this stuff last night, and he mentioned adding extra cooling volume. I didn't see how adding extra volume would help unless there was a corresponding heat sink that went with that volume, but I am glad you got some results out of it.
That fan in your thread is gnarly! I will keep that in mind. Good thread. I can't remember if I had seen it before, but I've only been back here on PY since 2024.
My nylon flex fan showed up today, the one that Sirrotica recommended. When you say the pitch of those blades is steep, you are NOT stretching the truth!
The leading edge of each blade is flat, while the trailing edge flips up at about a 90* angle. I will install it this weekend and see how it performs against my baseline data from last week. I don't think I will see 67 degree night time temps for several months, but it should find itself in the 70's for a night cruise.
I am still going to look at the possibility of squeezing a radiator with a 28x17 core. Bigger radiator=more cooling surface area. This could also open the door for a bigger/better electric fan setup, maybe even a 28" wide Silverado dual fan from 2005+. Just 2.25 inches wider each side from what I have, based on seeing one of these:
https://www.ebay.com/itm/256504481391