I have a SM465 to a NP205 now and found a guy who has a 3 speed to a NP205. for a OK price my step son want to put a manual in his over his stock 700R4 and 208 but I don't know anything about the 3 speed it use to be on the tree but has moved to the floor. How much difference is there in the 465 and how low is it? Thanks