Continued investigation and daily-driving road tests by my brother along with the help of listers' comments has pretty much convinced me that it's OK to drive the car home Denver to Detroit pretty much as it is. The fuel leak is very small and appears to be from one of the braided-fiber-covered rubber fuel return lines. I'm going to buy a section of that hose and carry it with me along with the classic "road tools".

Motor mounts cause irritating vibration only at idle, fine rolling under load. If heat doesn't work I'll just dress warmer for the trip if bypass of malfunctioning water valve proves impossible. I have a feeling the heater control valve is just stuck, the car sat for a long period at one time and it came up non-functional after that. All other climate control functions seem to operate just fine, even the A/C, which maybe needs a recharge to improve it's overall "coldness".

Will fix heat, install new motor mounts and replace any questionable rubber fuel hoses, belts and filters back home in my shop. I don't forsee any problems that will stop me. There is also a broken driver's side front window regulator "chassis", probably gonna need to scrounge one of those. The car looks very solid overall, though! Just seems like a heck of a lot of great machinery for the bucks and I have learned to be VERY handy with VWs and Porsches - why not this? I'll keep you posted.

Thanks again, please continue to supply heater repair tips.. 1978 300 SD. Dave Larson