If the needle in the needle and seat assembly is worn to the point where you would be fouling plugs on gasoline; it may be just right for E-10. LOL

The following are our recommendations for street use of modern fuels with and without ethanol:

Modern fuel/no ethanol - lower float levels 1/32 from specification
Modern fuel/ethanol E-10 -lower float levels 1/32 from specification,
increase main metering circuits fuel flow by 5 percent.
Modern fuel/ethanol E-15 - lower float levels 1/32 from
specification, increase idle jet flow by 5 percent, increase main
metering circuit flow by 10 percent.
Modern fuel/ethanol E-85 - nope, not going there at all, good luck to
any that try it!

If the customer resides at a higher altitude than 4000 feet, then a
different calibration is used.

If the customer tours with the vehicle, and passes through different
major altitude variance; we suggest the use of the Carter AFB, and
cut custom metering rods for different altitudes.
Typically "standard" calibration is used for sea level to 4000 feet;
1 size lean from 4000 to 6000 feet, 2 sizes lean from 6000 to 7000
feet, and three sizes lean from 7000 to 8000 feet.

Jon.


Good carburetion is fuelish hot air
The most expensive carburetor is the wrong one you attempt to modify.
If you truly believe "one size fits all," try walking a mile in your spouse's shoes!
The Carburetor Shop