My 98 cadillac deville concours keeps over heating i need help

Possibly head gaskets which are difficult to repair correctly. http://www.northstarperformance.com/sgstuds.php

Run strong still no power lost

Try a full cooling system service - new hoses, flush, t-stat and coolant and make sure the cooling fans work properly. You may also need a new radiator if flushing does not bring the temps down.