For any one in the future who may have a weird cooling issue.
My 2004 WRX cooling issue. I pulled the engine to do a ton of work, put it back in and ended up with a cooling issue. The coolant flowed, heater worked great, thermostat and pump worked great (all new) did not over heat, but the pressure would build up in the top and bottom radiator hoses (silicone) to the point were I thought they were going to burst. At this point the bottom hose would have so much pressure built up that it would leak, not a big leak but enough to smoke off the headers. I burped the system a few times to no avail. A mechanic buddy of mine told me to jack the front end up as high as I could and try burping it again (tires were off the ground about 4-6 inches) and whala! FIXED! I guess some cars may hold a small air pocket in the system that may not come out on a level burp? Or just the 3rd times a charm? Anyway this drove me nuts so I thought I would put it on here for the small few who may run into this situation.