I had to replace the heater core a few years ago and it was a hassle. Since I will be pulling the engine to replace a freeze plug going bad I am thinking about bypassing the heater core when I reinstall the engine. Really don't use the heater down here in south Texas, so this may be the time to bypass a future problem. Have any of you bypassed the heater core and run directly from the water pump to the head? If so, how did you handle the 5/8" vs 3/4" difference? Thanks.