As long as it within the 2 marks......Mine is at the farthest mark right now and I haven't run the engine yet so the belt will stretch a bit and it will settle back I expect. If you are running the Sanden compressor it is 2,490MM. At least it was for me. Stock size for an 88 Camaro with a 350. They go up by 20MM in size and it adds about an 3/4inch to the length. They supplied a 2,470 with my kit and I think they assume you are running the AC delete. I picked up a 2,490 and 2,510 and returned the 2,510.