Thank you! I would like to stick with the Carter and cast iron if reasonable, and I am happy with the current power. I have done the ignition fix up , with rotor, cap, wires, coil and plugs, but have not started on the intake. Maybe boil the manifold and rebuild the carb? Maybe a new timing chain set as well. Thanks for your help , and all the accumulated wisdom here. I have currently read up to page 180 of the thread.
Does the accelerator pump squirt strong? If so I'd then look to the fuel distribution/spray from the jets. It that reasonable, all you may need is some carb cleaner in the gas for a few tanks. I can't imagine what you'd need todo to the intake manifold, though.
If you are going to go to the extent of pulling the engine apart, you Could gasket match the intake to the heads, and the exhaust manifolds to the head. That (done right) would gain you 20-30 hp, for only the cost of gaskets and grinding stones. Just a bunch of labor mostly. The better flow would make it more efficient, and produce better mileage IF you could resist using the extra HP.
However this is not a recommendation,,, unless you just need something to do.
Of course if you want to spend money, Fuel injection, headers, new dual plane intake manifold, would save you some weight, as well as giving you more 'bragging rights'. Just kidding.
You'll probably not ever get more than 8-9mpg, because it's always running 'loaded'. My old 1976 Powerwagon PU super cab 4x4 only got 10 empty With a tailwind.
2011 Dodge 1500 C'boy Caddy
2000 Jayco C 28' Ford chassis w V-10 E450
Doghouse 36' or so Trophy Classic TT
Just took some pics of the carb and discovered I have a Holly 12r 4761b. I pushed the squitter a few times by hand and got a good squirt, so maybe the accelerator pump was stuck. The choke opens after a couple of minutes, and the intake manifold under the carb gets warm, but not hot. There is an iron wheel, attached to the right exaust manifold, maybe two inches in diameter, and a 1/4 inch thick, that can be rotated against a spring return by hand, but which does not turn on its own. I assume this is the butterfly valve for the exaust manifold for redirecting exaust under the carb when cold? Should it turn on its own when warming up?
Is the Holly a better carb than the Carter? Any trouble spots to look out for?
With the squirter now working, the engine starts quickly when cold.
Note that after it sits for a number of days without being started, you will have to pump the gas pedal a few times before it will start. At first I didn't do this because I was afraid of flooding it, but without pumping it some it won't start. I have never had it flood on me.