In addition to the changes I described above, the front radiator mounting points have to change. I had already removed them when I built my hidden harness bar, but I had to cut them down further to make room for the double stack. All I left was the mounting pad for the cowling:
I mounted the radiator stack to the rear mounts using the lower radiator mounting ears. At the front, the radiators are resting on the cut-down brackets. The double radiators fit pretty nicely!
Attachment 243739Attachment 243741
There is no room for the overflow bottle in it's normal position, where it also restricts air flow through the radiator core(s). It "might" be possible to shoehorn it into the opening at the top of the cowling, but for sure there is room to install it between the radiator tanks and the cowling on the passenger side.
My next decision will be how to plumb the two radiators. My fallback solution is to make a pair of thermostat housings and give each cylinder it's own radiator. I would use the OEM thermostat housing (without a t-stat) to combine the two circuits and feed the water pump. One or more of the UTV cab heater companies make such thermostats, but it would add a fair amount of cost.
I am hoping that I can run the two radiators in series, plumbing the outlet from the lower radiator to the inlet on the upper radiator on the passenger side. I'm wary of how much the second radiator might restrict flow, probably because I very nearly ruined an expensive pro-built cylinder head on my race car when I tried to use a radiator that had been sitting on the shelf for several years. It was so corroded that the pump couldn't move enough coolant. I don't want to repeat that! My next step will be to see how long X amount of water takes to flow through one radiator, then add the second and see how much longer it takes. If there is a big difference, I'll go with the dual thermostat setup.
The one thing that I am certain of, is that this setup will be a PITA to burp. I've been wondering if I could install a bleeder into the plastic tanks, a lot like how a metal tire stem is installed in a wheel. Maybe I'll see just how hard it is to burp before I take that step.