Sad Story On a Gear Vendors OD

1 to 1 to .68 to 1 is a big jump! all my gear splitting and OD knowledge is big truck related! a rto 13 splits top 4 gears with 12th at 1 to 1,and 13th .78, but my favorite, the rtoo 10th is 1 to 1, 11th is .92 to 1, 12th is .82 to 1 and 13th is .68 to 1 but takes a big hoss to pull it out at 80,000 gross!!