I recently installed a 94/95 cobra upper and lower. On the testing run in it started overheating and blowing all the coollant out of the reserve. I tried every air bleeding method and ended up with white smoke out the exhaust. I Finally decided to remove the heads and change the head gaskets. Put her back together and same problem but without the white smoke. The heater core stops blowing heat and up the temp goes. I have a 180 thermostat and power pulleys. My motor is a 91 with original heads and changed everything else over to 94/95. With an open cap fill it keeps bubbling. Any and all ideas welcome!!!!!!!!!