Oversize inlet valve, 1.4" dia, 3.57" long for 1275 head. Use 88G459
As it is possible, even common, to swap one head for another on 1275 engines, it is quite easy to become confused, or worse yet, confuse the parts-guy when it is time to order new valves!
Be aware that if the head has been worked on previously, it may have oversize valves; it may have undersize it seats have been installed.
Unless you are 100% sure what is in your cylinder head, it is a good idea to remove a valve for accurate measurement.
There are two lengths used (nominally 3.44" & 3.56") three different cotters(keepers), (wide, narrow, and three-groove) and many different head diameters! These valves were used on the Cooper S and MG1300 in 12G940 head castings.
TAM1059 alternative valve will require correct 3 grove valve cotters CAM6975.