I have To deside which is best i run a 2.78 upper and 6# lower pulleys, ok question what is the difference between 2.60 and 2.78 in boost instead of changing to a machined snout why not just change the lower pulley to 8# would this not be the same difference. In the upper pulleys 2.78.2.60 what about 1-1/2 boost would be difference. please help me do the math on this i run a built motor.

 

It's always better to go with the bigger bottom pulley!

Phil