Folks -- What's the impact of the lack of manifold heat control valves or heat risers I believed there called. My G has the valve shafts cut off to the manifold and obviously missing the associated left and right thermostats and hardware. I have also seen this on several other older cars over the years. In my case I have noticed the engine takes several minutes to warm up - result of the valves missing? Are there other issues to consider? Haven't looked into yet -- these valves available to re-install? Regards -- Myles http://www.nauticom.net