furnace install

So I'm finally installing my Furnace - Suburban w/ the Stainless Steel Cover/Cap/Trim that goes on the exterior (for the combustion air intake and the combusted air exhaust). Because of the sloping exterior wall, especially down near the floor, the furnace has to be set at an angle so the outside trim/cap will slide in tight against the skin.



I didn't find anything in the literature saying the furnace must be level to operate but I wanted to find out if anyone knows for sure. And are your floor mounted furnaces installed level? Or are they angled?



Thanks.



Also, the literature points at the top "lip" of the exterior trim piece and says, "provide sealant" . . . I'm assuming this trim piece will get fairly hot - can I use Trempro/Vulcom Or do I have to find something designed for "heat"?



Thanks.