I will be very surprised that your timing side crank shaft journal is both truly round and truly cylindrical, commonly known as ovality and taper respectively. However if it is within wear limits (which involves measuring at the front of the journal across diameters at 90 degrees to each other and then the same at the rear), that is good, but you will still find that your "ordered to size" bush will still arrive undersize to enable it to be "line bored" to size after fitting. The actual fitting process will distort and crush the hole very slightly, which is why they bored after fitting and that process also ensures that not only is the bush of correct size but also both main bearings line up exactly. I suggest that you locate an engineer in your area to fit and size the bearing for you. It is a job that you simply cannot buy the part and expect it to fit correctly.