Grab a cup (and fresh pot) of coffee and get comfortable ... 'cause here I go again.
My Little Project (MLP) is the latest iteration of a desire of mine that's spanned almost a half century.
One of the primary goals of MLP is 20+ MPG out of a Class A motorhome.
Engine (and transmission) is a 318-3 out of a 1969 M300 Class A. 'New' chassis is a 1973 RM350 Class A with the next longer wheelbase than the M300.
I had used the M300 (and OEM 318-3) for several thousand miles in Alaska's often mountainous terrain. (What Lower 48 people -- especially on the east coast -- call mountains we call hills.) I was very satisfied with the performance and I have a soft spot in my heart for the Mopar 318. (Some of you may say I "have a soft spot in my head" ... I'm comfortable with that.)
OEM 318-3 had leaded gas heads. The heads were also a special, late-60's 'cold weather package.' Instead of re-routed exhaust, these used engine coolant to preheat intake manifold. So heads and two-barrel intake manifold absolutely must be used together. (Special 'cold weather package' was only offered for two or three years so the heads/intake manifold combination is extremely rare.)
I wanted a four-barrel carburetor instead of the OEM two-barrel Carter BBD. So, in addition to unlead gas heads, I needed a different intake manifold.
I found a set of unused -- never had valves in them -- unleaded gas 318 heads on eBay. Heads had been sitting on a shelf in an Air Force warehouse for decades. Seller was in Nevada, heads were in California, the people I wanted to build the heads were in Maine, and I was/am in Alaska. I bought the heads, had the seller ship them to Maine, where the engine builder checked them out before the sale was final. (I wish I could have gotten 'airline miles' for heads ... California to Maine to Alaska.)
To be continued ...
