Just a warning to any of you who have bought or may buy the plastic heater valve, available at most Bronco vendors. Today I took my grandfather for a short ride down highway 52 in my 68 Bronco (with a brand new only 300 miles 5.0 HO motor). At about 65 mph I started smelling anti-freeze and looked down at my gauge to see temps about 230. I got it shut down and found that the brand new plastic heater valve bottom had came off. It leaked out water as fast as the pump was pumping, my system was completely drained in seconds. Fortunately I don't think it did any damage to the engine, it may have voided my warranty heat tabs though. Just wanted to prevent anyone else from the near heart attack I had today. I ordered a metal one as soon as I could. Here is the proof: