So apparently all they did was move the old HE up into the radiator stack. Your dims are exactly the same as my 2016 for the original HE.
I drove from Austin to Houston yesterday and watched IAT vs ambient all the way home. IAT was never less than 25* above ambient and mostly closer to 30*. This was at anywhere from 70-90mph. I don’t really want to spend the money on the bigger cooler but I’m also not sure fans would help in this situation. My HE is directly behind the bumper grille which is wide open on my truck. What can the fans do that 70+mph wind can’t?
I guess I’ll just build my own fan kit to keep IAT down in heavy traffic situations and forget about it. I had enough power to walk a Trailhawk Jeep from a 70 roll...that’s good enough for me.

I think you are on the right track

Do you feel like the cost benefit was there on yours in slow traffic situations? Unless I missed a post it looks like your cruising deltas are within a degree or 2 of mine. I guess that’s as good as it gets for cruising.

cost benefit was there for me.

my delta was 40-50 degrees with the kit the way it shipped.

Now its 25-30 degrees. I could literally feel the power fade as the temps climbed (I think Whipple had too much timing being pulled at higher iat temps - much better with the current Whipple tune)

On the way to South Padre today and about an hour ago was running IAT 22 degrees above ambient at 75 MPH. It is normally between 22 and 30 above ambiant. That is with the high capicaty heat exchanger.

So it kinda sounds like the small HE works well on the 15-17’s in the low position with good airflow but is too small on the newer trucks moved up into the radiator stack. I would think it would perform at least equally as well but y’all are seeing a completely different result if it takes the big HE to get things back into the <30* delta range. I’d like to see one of you slap some 13” pusher fans on that big bastard and see what happens then.

the reason the 18 doesn’t get a fan as an upgrade is the lack of room with the grill shutters.

the big HE or LTR is a better candidate for a fan with the added room higher up and away from the grill shutters.

The shutters are always opened with a tune anyway so I removed mine. Now there is space for a pusher fan.