Cooling air inlet duct opening.

[Flyboy66]

Alright. I have radiator attached to oil cooler. Waiting for some SS from Kitfox to make the brackets for hanging it on the airframe (aluminum temporary straps for now). It says to set it on some 3/16” shims on the floor if the cowl, but there is a ridge across the bottom (can be seen in comment before this one), and if I put shims under it, the radiator will extend even further above the duct. Modifying the duct is no problem, as I am a fiberglass guy, but I am wondering if this is the way everyone else is doing it. Picture is without shims under radiator.

I am inclined to cut the top of the duct and extend it up further to fully draft the oil cooler, and while I am at it, I think I would extend the sides if the duct back to force the air through the radiator rather than giving it an escape route around the sides.