[Gooserider]

Hmmm... No personal experience, but when I see 'Hayden' I think Transmission / oil coolers. Is this cooler originally designed as an oil cooler?

All I've seen on the subject suggests that oil cooler style rads are not as good at cooling as heater core style units. This isn't to surprising since the two were designed for different working fluids, and different Delta-T's, and the heater core design is closer to what WC folks are doing.

Not sure how to calculate the cooling benefit of higher flow fans, but I wouldn't expect very much. (but it will make your system louder...)

What kind of temperature drop are you getting across the rad? If the output's about the same as the input temp, then you might get some help. If there's already a big drop you probably won't gain much.

If your current rad is an oil cooler design, then you might benefit more by replacing it with a similiar sized heater core type unit if you can.

Gooserider