On your temperature issue, I’ve been fighting a similar issue on my new cooling set up.  What I’ve discovered is that my evaporator cores are not allowing coolant to flow evenly through them.  At least at lower power levels.  Only the top ¼ is getting hot. 

 

I can't recall where your hoses entered, and exited the evap cores.  I'm assuming they enter and exit the top side?  Are they parallel, or series?  Do you have a thermostat?  Very odd that only the top portion would get hot, unless the hoses are on the top, and you have a thermostat that's limiting the flow to a trickle.   

 

Originally there were tubes on one side that extended down into the side tank to force the coolant (freon originally) down to the bottom of the core.  When I drilled out the cores to install the AN-16 bungs, those tubes went away along with the top plate material. 

 

Now, I have some ¾” aluminum tubing on order, and I’m going to drill big holes in the bottom 2”, and insert it into the core to perform the same function.  

 

I don't think you're going to gain anything with those tubes.  As Tracy said, when you think of water flow rate, don't thing straw, think fire hose.  Water will be forced to use the whole core.    

 

I also had a devil of a time getting the air to bleed out.  It would circulate coolant when it was parked on its nose, but not when upright when I would taxi.  That drove me nuts (not a long trip anyways).  

 

Are you sure you did finally get the air out?  I ended up adding bleed valves on the top of my cores to use when filling.  They work great.  You're probably going to want some sort of air bleed valve in the system to avoid the hassles of having air pockets when filling. 

 

 Cheers,

Rusty (still thinking about the MAP comments)