another 360/408 over heating

Dang. That sucks. O did a quick search on champion radiators and it appears that the 22" 2 row have .75" tubes.

The 3 row are exactly the same except the core of 26" wide. How big is your radiator support opening?

I'm not sure a 7 blade fan will be very effective without a clutch, but I don't think you can fit one. How much space do you have between radiator and Water pump?