But I think it'll do.
I wanted to incorporate a thermostat housing into this , so mission accomplished.
Took a 3 X 5 X .375" shear drop for the top......milled it square and cut a .125 lip into it to make it easier to weld the sides , which are .125 " , to it. drilled and tapped the top for the thermostat housing and plunged a 1.5 " hole in it.
Drilled six .750" holes in one side for the AN fittings and bent a 90 degree in the two side pieces to eliminate two seams.
Cut a piece for the bottom , then welded , pressure tested , welded , pressure tested and finally welded and pressure tested it.
A good friend has a TIG and limited experience welding aluminum , so we had a few pin hole leaks that needed plugging.
But after three tries and much cussing , we got it to hold air. I looked high and low for something commercially available for this. No dice.
So until something better comes along , I kind of like this one.