Mech fan suggestions…..

I assume your rad is aluminum.
By any chance do you have a copper / brass in good (CLEAN TUBES) you could swap for testing?

Seems like some Al rads are pushed to the rear of the car by core thickness and mounting brakets.

Stock copper/brass can be 3 row with the extra row to the front.

You could open up the 22 inch rad support to accept a 26 in rad.

You could add high CFM pusher electric fans

High flow thrmostat, propper ratio pulleys, high flow water pump.

In all reality 200 to 210 is not all that hot.

220 is starting to push things.

Recently in another post i posted some radiator design info and they were talking that fins per inch was the most inportant aspect to a rad because ALL of the heat transfer from the tubes takes place at the point where the fin is soldered to the tube.

Good luck

I'm running a Griffin 26" aluminum rad 3 core. I was told (right or wrong) that this was the largest rad they make or that I could fit. The height is good as it sits , but the outter edges sit outside of the cross support opening and don't get any cooling.

I have a hi flow 165 degree stat, high flow water pump, but frasnkly could take a look at the ratios of my pullies - my power steering pump whines like it's low on fluid (and it's not low) so I think the ratios are set for max hp and less for spinning the pumps (ps and water) at the right rpm.

I get that 210-215 isn't necessarily "hot", but the motor builder said no more than 220 or I'm seriously risking damage to the aluminum block - true or not I trust him and am taking him at his word - Id rather not see how far I can push it before something fails.