I am getting ready to order a new electric puller fan just released from Flex-a-lite; 2500cfm and only 3-3/16" deep. I also plan to order an adjustable temp controller; what’s the most accurate probe to use: threaded in the intake manifold or a probe thru the radiator fins? I am thinking threaded is more accurate since it’s touching the coolant just like the temp gauge.

Thanks in advance for any responses.

I prefer running in the intake manifold more accurate reading and less affected by air temp. "I live in Wisconsin."

I think the threaded sending unit not only works better, (since it's submerged in coolant, instead of taking a reading from a metal fin) but it looks better for a clean installation. I would install it in your radiator. I've seen a lot of guys running electric fans with a thermostatic wire shoved in between the upper radiator neck and the upper radiator hose. To me, it just looks kinda cheesy. Good luck!