My 68 Charger 383 HP engine is becoming fickle. First it appears to completely dislike the premium grade ethanol based fuel I use. Once it reaches operating temp it has a hard time re-starting. I blocked the intake manifold cross over (left exhaust manifold exhaust air to the right side of the manifold for the old bimetallic choke) passage hoping it would not cause the fuel to boil/evaporate out of the carb after sitting for several minutes to almost an hour. I replaced the fuel pump and filter with no luck and cleaned out the fuel line from the tank to the filter. The car cruises down the road with no issues at cruising speed (40 mph and up)and responds well when I hit the throttle. But when I cruise at low speeds, 20 mph or less, or sit idling for several minutes and the water temp starts to climb the car responds poorly. It spits and sputters and acts like it's starving for fuel. Could it be just the ethanol based fuel, could it be a bad rubber fuel line at the tank sending unit collapsing, could it be water in the fuel? It has a new Edelbrock 750 cfm carb up top of a stock cast iron manifold. I will be putting in some fuel treatment for water but after that I am at a loss...... Any help is appreciated.
mikeymopar68 AT aol DOT com

I'd run some non gasahol & see if that's strickly the prob. what changes right b 4 the prob started? Gasahol absorbs water so no water treatment needed. which side did you block the heat riser on as it kicks back ex for heat from the pass side. A felpro ~3/8" carb base gasket will definitely help and finding/making a laminated wood spacer is the best. I run 89 octane E10 (gasahol) and 87 octane non gasahol regular w zero probs & runs identical either way in a DD 318 65 dart w streetmaster/1406 Eddy but it does run cool.

Do you have a good insulator/spacer under the carb? That cuddy new style gas may be boiling away easier than the old stuff. Having the riser blocked is good but may not keep it cool enough.

Let me be the first to say the 1407 is junk.

Thanks guys. I may just give an insulated carb base spacer a try instead of resorting to replacing hoses on the tank. Finding nonethanol gas may be a problem but I will ask around. I run 93 octane since it does not like anything lower. I blocked off the left side of the intake manifold where the exhaust air is channeled to the right side of the manifold. Somebody bring back the Sunoco or Amoco top grade fuels please!!!!!