Believe it or not, I can get Kerosene locally cheaper than I can get fuel oil. So, needless to say, I just dumped 100gal of Kero into my tank.
The question I have is: Do I need to change the nozzle in the boiler to run Kerosene instead of fuel oil? 
The boiler currently has a .85 80*B nozzle in it. I have spares in both a .65 70*B and a .75 70*A. What do you recommend? Thanks in advance for your time.
Nope,.... No reason at all,.... Kero is just slightly lower Btus per gallon,...
It's used interchangeably up here in the frozen north, dependin' on prevailin' temps, 'n how the oil in stored, inside, or outside,...
#2 will gel at lower temps, #1 don't,...
Hard to believe #1 is cheaper than #2, especially here in NYS where energy is like Gold,....
'course, I guess it is Gold, atleast in the State's coffers,...