Underdrive pulleys and overheating?

I ealizr this is an old thread. But i have the same tru trc setup on my 73 duster 360 /400 hp crate. I started with a champion aluminum 3 or 4 core radiator
And the champion shroud with two 12” spal fans for a total of 2600 cfm.
It overheated like crazy!!! I mean it wanted to climb to 240. It was bad i even tried clower hose coolant restrictors of different sizes and no better . So i decided to put on a set of ford contour fans. It fits the core nice and i used a seal as well , dakota digital fan controller
The radiator and fan ar so thick i had to machine the nose of the water pump pulley doen to the bolt holes. And it still touches the fan shroud. Anyway. These fans have cooled 700 hp big blocks without issue. It still ran hot this summer. Not as bad. Now that its winter time. I can take it out on a cruise and it will run at 190. As soon as i come to a stop it starts to climb to 210 or higher. Mind u i have a trans cooler and an ac condensor ( ac is not working yet). But honestly i think it may very well be a the tru trac. I had the same setup on a 61 F-100 with a 521 scj 600 hp crate motor. And i had the 1800 dollar be cool 1000 hp cooling module. And it did the same damn thing. At a light it would just start climbing in temp to the point i would ger back to my shop and shut it daown and it would diesel. Anyway i sold the truck without the motor. I took the tru trac off and sold the 521. I now have it ona 380 hp 460 in a 66 f100 4x4. But i did use a stock water pump. I havent tried it yet but hope that ome is better. Im just about ready to ditch the 3k dollar pretty *** fromt accesories and just throw a regular belt setup and pulley setup on it. Idk if the tru trac is underdrive for the waterpump or what but it sucked on both vehicles. I now have the same setup for my gtx with 540 hemi and i hope it doesent iverheat when finished. Idk. I havent found the solution yet.