Soo couple of years back did a pulley change on the tranny from 6 inch to 4.5 and used a 1/2 X 79 belt to make it work and it worked fairly well but wanted to get back to a 5/8 drive belt so went to a 5/8 x 81 inch belt and added a second flat Idler pulley. I simply cannot believe how smooth and sharp it shifts and drives now! The added flat Idler was 2 3/4" with a 5/8ths bore used and existing hole on the side shroud and just opened it up a bit. I use to slip a bit on steep hill with the 79" slips no more, the belt drives and the clutch is LOT smoother and in the right pedal area.... Will see how it holds up cut 3/4 of an acre of grass yesterday NO issues.