Now I had a chance to look over a 430 at a local shop. It gave me an idea as far as laying the engine out. TH e430s run with a radiator at front, with the radiator fan running not on the water pump, but on a pulley up front. If I were to configure the layout so that the engine is pushed as far back, still allowing air to pass the pulley side, and then place the radiator up front. That would allow the for a larger radiator up front.
With that being said, I can find a radiator with a electric fan, or find a way to run the draw fan off the flywheel. I will still need to run the manual PTO of the flywheel so, I might be able to lay the radiator at an angle. I have found one radiator for a snowmobile that can lay at an angle some being 2 deep, but no 3 deep. They do come with the elec fan and sensor.
What do you think?
I don't think there's a snowmobile radiator that will give enough cooling for your diesel. Remember that snowmobiles are made to run in cold temperatures so that is taken into account in their cooling systems. Also, a diesel puts out a lot more heat than a gas engine of comparable displacement--I don't think you'll find a snowmobile engine that generates the heat your diesel does.
I think putting the radiator in front is a good idea. You can run an electric fan mounted against the front of the radiator, and still have room for your PTO, etc. You'll have to run some tubing from the water pump back to it, but it's doable--others on the forum have done the same, plus I think one of the Bolens Diesel GTs (not the Isekis) used a similar setup, just can't think of the model number.
I plan to buy one of the Honda 3 core aluminum radiators on eBay--$102 delivered with a fan is a great price.