Just about any compression ratio will benefit from the extra torque of alcohol. I wouldn't think twice about changing over with any ratio.
I respectfully disagree with the electric fuel pump not working. You can't say that not knowing what pump. I know many people running electric fuel pumps and alcohol. I am doing it myself. The best plan to run electric is using a return style regulator, but it still can be done deadheaded. I suggest the large Holley regulator #12-704. You should have a GOOD pump. I use the Aerospace 400gph pump. At least -10 from cell to pump. -10 from pump to regulator is best, but -8 will probably work. Then -8 to carb bowls. Whatever line you run to the front if you use a return regulator run the same size back.
Alcohol is much easier than many people make it out to be. Watch how rich your idle circuit is. Get you engine oil and water temp up really good every time you put it away and it will help keep the oil clean.
With all that said the belt drive pump is the best, but by no means required.
Curtis