I fabricated a fan shroud for a 22" - 4 row brass radiator, but will it be enough?

I bought a custom radiator spec'd out by US Radiator several years ago for my '68 Barracuda. It effectively cooled the Magnum based 408" stroker that put out around 380 RWHP with an A/C condenser in front of it. I was running a factory radiator fan and clutch.

I am now upgrading a similar displacement motor to 820 flywheel hp using a Paxton style supercharger, and I'm wondering if that same radiator with a 16" Zirgo electric fan with a custom fan shroud will be enough to cool it. I don't like the look of aluminum radiators on old Mopars.

I made a sheet metal shroud that stands off about an inch from the cooling fins and is relatively tightly sealed around the perimeter of the radiator for maximum flow through the fins. The tech guy at the fan supplier stated that I could always use two 12" fans to gain even more flow if I needed it.

I'm curious what experiences some of you have had trying to cool higher output engines with a 22" radiator.