Conventional thinking has it that 340's are more rev friendly due to their shorter stroke ie. 3.31 vs 3.58 for the 360. I am not so sure that I buy that argument. When using the same brand and model piston, the 340 piston will be heavier due the greater compression height required. It seems to me that the heavier piston pretty much negates the advantage of the shorter stroke. Now a 340 may need to rev higher than a 360 to achieve the same power, but that dosen't necessarily mean it revs quicker. Given cost, availability and probably a broader power band, I would go with a 360 in most cases.