I have probebly gone though about 1/2 gallon of coolant this year and everytime I drive it goes down about an 8th everytime. Its a 383 with felpro 1010 gaskets and TF Aluminum heads with ARP bolts. I have 0 leaks that I can see. The oil looks perfect. Temp never goes over 200 and plugs look perfect. Oil level always at full and good oil pressure. I smell no fumes in the radiator. Spark plugs all look normal. No smoke. I'm at a loss here. I was wondering if I should retorque the headbolts and see what happens. Also with a 10:5:1 motor what should compression be like? I'm going to do a test tomorrow.