I'm running a 8.75 x 2.75 but I'm not selling it. 8.75 is the stock length but the 2.75 is .25 more than stock. I put a couple of rubber washers under the bumper to be safe but I almost think it might not need them, didn't fully test the stroke to see if the shock rubbed anywhere. The bike is so much better with the coil. Bottomed out the air all the time. No bottom out with the coil. Spring is a 450x2.8