Guys if you have problems with your heater core leaking DO NOT just block off the pipes that go into the heater core and the return . Make sure that you rejoin them if you are going to delete the heater core from the system. i have seen about 4 cars now with the pipe blocked and this line is the main water line for the head.
!!With this blocked your motor will DIE !!
Make sure you rejoin the pipes to create a complete circuit for the water to flow.
what i will do when my heatercore leaks is run some radiator sealant through the system the core is leaking already so you car is wet, its worth a try and im sure it would work.
Please dont kill anymore vr6's
cheers brenton