Radiators: Is 22" enough for 400 HP?

Hi! I've been trying to research the heck out of this.

I have a nicely built 360 that has been dyno'd at 403 HP. I was built by IMM Engines in Indio,CA. So far, runs great but it gets a little bit hot. The needle is over 200 degrees.

So, I've come to the conclusion that my stock 19 inch radiator with stock mechanical fan isn't cutting it anymore. I have been looking at aluminum radiators with the larger 1 inch tubes in the 2 row configuration. From what I read, that seems to offer the best cooling.

The question is:

Will a 22 inch radiator with 2 cores and 1 inch tubes with a stock fan and no shroud (at least for the time being) be adequate, or should I go with a 26 inch radiator with the 2 cores and 1 inch tubes?

I have been looking at Champion Radiators, American Eagle Radiators, and US Radiator since those are what my budget allows right now.

I'm leaning towards the 26 inch radiator, but seems that the 22 inch is easier to find in stock and I would like it this weekend.

Thanks!