[bigblockcoupe]

well it's a heater core when you changed the hose was it the factory hose if it was inside of it it should have a grommet that reduces the diameter inside the hose to relieve coolant pressure on the heater core and if you don't reuse the grommet inside the new hose it will blow out the heater core everytime i've had it happen a few times i don't even have the heater core or tube assembly hooked up on my coupe or my cobra after i changed the heater core in my cobra twice (what a pain in the arse) i said screw it and just did away with it.