I run that setup in my daily driver, I thought I'd need the bypass more for plowing snow but the engine rarely gets that hot, the racing fan that's in there (I forget the brand) handles it well with the little shroud the electric fan came with. Moves a lot of air. I ditched the clutch fan on it probably 13-14 years ago and it works fine with a thermostatic switch (OT but a 5.0). Rarely, with heavy wet and deep snow, I've turned it on manually but mainly as a precaution.
The fan is wired to ignition, so forgetting it flipped on is not an issue - but in the past I have tried it off constant 12V and although with a good battery that was usually not a problem, they do drain the battery pretty quick if you accidentally leave it on.... don't ask me how I found that out.
In my 49 3600 last year I swapped in an EFI (TBI) 4.3 and for many reasons of my own I set the engine ahead and for fan clearance reasons I opted to run an electric fan off a thermostatic switch. I could have fit a slim fan in there, but... given my experiences in my daily driver I just ran the electric fan. I didn't get it finished until later in the summer so haven't tried it in the heat yet, but drive it a lot in the late summer/early fall so far if anything it's running cooler than I'd prefer. Rad size is obviously a factor there.
I didn't bother with the bypass switch in the 49 after seeing how well the thermostatic switch worked in my daily though.
Last edited by NorthCoast3800; 02/19/2022 5:40 PM.
