[tazdevil]

I think you are under cored for 500 HP, by a bunch. For a fan, I'd recommend an electric that flows minimum 3000 CFM. Absolutely must have a shroud to accelerate air flow. I'm running 400 HP with a two row copper radiator, electric pump drive and 2000 CFM with no issues.

 

[core]

Ive done some more research and found that most of Griffen's radiator's cores are some what the same.
On their site I punched in 400 to 600 HP and the same size radiator came back as the one I got.
I'm going to wait until Monday and ask them direct.
I was going to run a clutch 6 blade fan (if I have the room). There is only around 2 3/4" from the water pump to the face of the radiator.
I have room in front of the radiator for the electric fan if needed.
The shroud will have to be custom. The original one will no longer fit.
Thanks for the help

 

[tazdevil]

Sounds like it might work. Aluminum cross flow is certainly more efficient. Wise to call them.
I think you'll have a fitment issue with that little space between the pump and radiator. The clutch adds to the dimension, and the fan blades too. Maybe a twin electric pull fan with built on shrouds could be thinner.