09assault800cfi to 07 600HO engineconversion

Hi guys.
Ijust bought a 09 assault cheap with an engine that "exploded"
The 600HO carb with wiring loom from 07 rmk600 is already in the chassie but the question is what to do with the cooler hose coming from under the termostat in the head.
This one goes to the front tunnelcooler on the rmk 600 and back to the expansion tank. Since the assault does not have a front tunnelcooler can i just plug it or do i need to get a 600 expansion tank that has the extra inlet for the front tunnelcooler and route it there? I would hate to have to install a front tunnelcooler on the assault...to much work
I must admit that i have pluged the hosebut i need some advice if its ok to do so.

Anyone?? come on guys..give me some input

ok. think i found the solution.
The termostat on the 600 is w/o bypass since it has the extra cooler.
So by using the termostat from the cfi800 with bypass in it i should be okey

A little update Sled runs great and everything seems to be working fine. The only problem that has come up is with the display.
Somewhere a wire has been crossed or put in the wrong place.
it changes from celsius to farenheit by itself? any ideas on this??
The 07 carb has the mode button on the handlebar and the assult on the tankpanel so the wires has been rerouted according to the polaris wiringdiagram.