Bro, been testing the Suruth Overdrive yesterday.
I can tell you that this man is genius
With 37F and 40R, 46T rear diff, 2.5mm tire split the car is not only easier to drive but the ability to cut the fast chicane is awesome no weaving anymore.
Start with full rear diameter(65mm) after abuot 7-8 tanks the rear became 59.5 and 57.5 in Front !!! Perfectly the same roll out with start diameter.
You MUST try this overdrive !