johnksss
the transition wont be a hard one. it just might take a few days...but if the card was bad and they said they were upgrading you...then that's when you would buy the block or blocks as well. and a 480 can run pretty high on clocks on just air. just dont over due the mem clocks is all.
as for furmark... if your trying to break the card...sure...run furmark for hours on end...
i would check for leaks on the card myself.
Fortunately I have an EAR on this card.
If I end up RMAing and getting a 480 I'll pick up an EK Nickle block probably.
Gonna run furmark for 5 minutes, then give it 5 loops of vantage, 3 of heaven, etc.
Leaks are a negative, temps were around 40C. Didn't red light, it's seated fine, not sure why it would have done that other than it's dying.
Edit: After Furmark it's still okay.