I measured and cut the 5/8ths diameter hoses to connect the liquid cooling system to the optional internal heater. This requires a supply hose, a bypass hose, and a return hose. Unfortunately, after cutting the hoses, I discovered the "T's" installed on the firewall for the heater were too large for the 5/8ths hose I had cut. I called Ran's Tech support and talked to Randy S. I sent him pictures so he could figure out what was going on. I hope to hear back tomorrow.