Bulleid also had the cylinders re-designed, with 10" piston valves rather than 8" and improved steam passages. All but one got those. Less obviously but still significant, this freed them up from having the same valves as the Schools. There had been a lot of tweaking of the lead and valve heads to solve starting problems with the Schools, and since the LNs had common components they got the same modifications. Unfortunately, the effect of these was to reduce port openings at short cutoffs and this was more of a problem for the way in which Nelsons were used than for Schools. The re-cylindered Nelsons could have settings to suit them. The high sided tenders as sported by 850 were also a Bulleid-era modification, as built the tenders were mostly similar to the one behind 847.