I need more room!l

That setup looks and sounds like a great job. Very clean and robust.

The air is probably pumping downward and recirculating from the bottom more than the top, since there is like 5 + inches of clearance under your rad support. Put an air dam on the bottom of the core support made of cardboard or stiff plastic and lots of duct tape for a test or something.

I had a 4" air dam below my core support before on a gm to help cooling and it did.

Or, maybe seal it up from the bottom of core support to the grille too so it forces it to suck thru the grille rather than from under the car. If the grille hasnt the air flow capabilities then you will need an air dam under the core support to prevent recirculation.