So, my 60 series shroud is 3 1/8” wide and the back of my fan is almost exactly even with the back of the shroud. Also, my 60 or 62 series fan sits 1 1/4” from the radiator. So, when I put on a late model 40 shroud, I should have almost 1” of fan exposed. Hopefully, that’s the ticket! Thank you for the measurements!
deal is: the fan should be covered just about half-depth by the fan shroud, not completely IN the fan shroud
yes, you should run a shroud, and NO, an electric fan won't do - there are plenty of people here on MUD who tried, and the cooling is never where it should be with only electric fans
you could source an "aqua" hub fan clutch, which is juiceable - meaning that the clutch can be opened to enable changing the viscosity of the fluid in the clutch - the thicker you go, the more often the clutch will be engaged = better cooling
Just wanted to update this thread. I installed the late model FJ40 shroud purchased from @wngrog and installed an OEM radiator I had in my parts stash. The loud noise is now gone and I'm back to driving with just the road noise of an old FJ40. It's music to the ears. Also, the temp never got above 190. Thanks to everyone for the help.
It is a little disappointing, though. Running late model 2Fs out of 40s or 60s is not uncommon and OEM late model 40 shrouds are a bit of a unicorn. Knowing that, I figured I'd modify a more ubiquitous FJ60 one. But, I guess the lesson is: if you want to go down that path, push the radiator frame forward as far as possible so that fan blade can sit back in the shroud as much as possible. Mounting the frame directly in the factory holes, puts the shroud even with the back of the deeper Fj60 shroud and causes ineffective cooling and a lot of noise when the fan clutch engages.