random overheating

[lovnthe70]

Hey guys i have had an issue with random overheating for a little while. It happens both at an idle stop and driving. its a very gradual overheating and i think the thermostat is working cause the upper radiator hose is hot and ive changed it out twice. I am running two electric fans and an aluminum rad, and pretty much the only thing i have not changed is the water pump. does this sound like it could be the culprit?? its a 454 with what i believe is a 4 core rad ( i dont know how to check this) and im not sure what the fans are rated at but they are pullers and seem to pull through quite a bit of air. my timing has also been set recently... any suggestions on where to start?