If the combustion chambers are 70mm then it's a Road Rocket or Super Rocket head. If you can get the magnifying glass out and try to discern the part number that would help. It is likely to be either 67-1126 or 67-1549 or 67-1549 overstamped 67-1571. BSA used the same exhaust valves on all the alloy head A10's which measures 1.382" (just over 35 mm), but there were three different sizes of inlet, 1.415" (36mm), 1.455" (37mm), and 1.5" (38mm) used broadly in line with the development of the cylinder head over time. If you can read the part number on the head you are on the trail of which inlet valves it should have. There were only two types of springs used, one type for the SR and RR, another type for everything else. Your springs, caps and collets look correct as they are different (as with the springs) to all the others. Springs should be 51 / 54 mm, whereas all the others are 39 / 48 mm inner / outer. You need to have the correct valve spring base and top cups as they are also different to all the others. Hope that helps.