55 eldo running rough

[onemadone]

A week ago I was parked on the grass on a slight hill, my nose facing uphill at a car show. When leaving I had problem getting up the hill, had to floor it to make it up and out. Immediatly afterwards I noticed the car felt like it was running rougher than before I got to the show.It felt underpowered climbing hills driving home, hesitated at low speeds. Parked in my garage I notice a stronger smell of gasoline than usual. Fuel filter and pump has been recently changed before this event. It's been running smooth all summer.  What could be wrong?

[35-709]

Recently changed items (fuel filter, fuel pump) are the first place to look.  Add in a strong smell of gasoline and it should be even more apparent. 
New fuel pumps from China are notoriously unreliable, rebuilt pumps are not being put back together correctly and are unreliable too.  NOS pumps (if you find one) are no better because today's ethanol laced fuels attack the old style rubber used in the diaphragms.  Best way to get a good pump is to have your old one rebuilt by a reputable rebuilder.  Someone here should come up with one, there are several known to members here, believe Arthur Gould is one.

[V63]

For reasons listed above... I have defaulted to all ELECTRIC, mount near tank!

cut the arm off the original pump and plumb around it or if creative enough plumb thru it so it appears fully functional.

Electric pumps are more blended fuel tolerant. Try to get the rotary type vs (older) pulse type.

[James Landi]

ANother possibility is that one of the carburetor floats is partially stuck open.  Run the engine, shut it off, and immediately take off the air cleaner and look inside and down the carburetor-- if you see a wet gasoline
film" flowing on the inside, you've a stuck float.  It might have something to do with parking on the hill, causing one of the floats to rise just a bit more than it has in decades, so it's stuck.  If the float is stuck, tapping the side of the carburetor with a hammer may release the float as a quick fix.( note: Having owned two '56's, those fuel pumps have a design issue--- having them mounted above the engine block and lacking lubrication, many of the original pumpss had a grease fitting... some of the old timer used to pack the mechanical/interior section with grease to ensure lubrication of the mechanism... without the grease, increasing wear would have the effect of rendering the pump useless as the fulghum pivot would wear out.)   Hope this helps,  James

[David King (kz78hy)]

I had one of the floats in the rear carb leaking, so it was flooding the engine.  Dayton Carb is making new floats if you need one.

[35-709]

Believe David King is referring to Daytona Parts, my apologies for the assumption if I am incorrect ---
 https://daytonaparts.com/