Heater questions

[exploderjim]

Forgive me if this is a silly question. Is there a replacement heater defrost system for these trucks that doesn't require coolant lines. Maybe a electric system. My question is based on if you shave all the heater holes from the fire wall how do you get heat or defrost. This seems like a dumb question even to me but I want to completely shave the firewall smooth and all I've found so far require coolant line to get the heat. I thought they would have made some sort of electric system. Any help or advice would be appreciated. Maybe even a picture or two of how guys have theirs set up.