(I also posted this in the E-Revo forum) O.K. So what I have done is converted my Summit to a E-Revo, so I can race. I switched from stock Long Rockers to Progressive 2, and I have installed some Proline 40 series Bowties. Now what this has changed of course is my ride height and front and rear track. Now as per parts list for both vehicles the tranny is the same, only difference being this thing has a low gear. Now what I was wanting to know is where I switched from the stock Canyon AT 7.1" X 3.8 tires to the 5.5" X 3.8 Prolines, how does this change my overall drive ratio? And what gear ratio should I run for racing. And for now I am still stock in the motor area, the only difference is instead of having two 550's I have one 575.