Good Day!
Please forgive a question from someone that knows close to nothing about such things, but I would think the temp to monitor would be EGT. It would seem that cooling intake air would certainly affect coolant temps, but the real goal is to get the charge air temps down, which should show up pretty directly in your EGT gauge.
I'm asking so I may learn, not because I think I know something about this - I don't.
Thanks & Blessings!
82 6.2NA K15 4X4 pickup, 4spd man w/ OD, 335K+ "In Rust We Trust" (parked)
95 6.5TD 2500 4X4 pickup, Gear Vendors Aux. OD, > ¼ million miles - gone
95 6.5TD 1500 4X4 3/4T Suburban, Kennedy exhaust, > ¼ million miles
93 6.5TD 3500 4X4 1T crew cab LB pickup, 230k miles