I asked at an engine shop the other day about buying some new inlet valves for a CA rebuild. When he got back to me he said "there's 2 different sizes of inlet valve (different length) on those engines so we need an old one to messure it"
AFAIK there were indeed 2 part numbers listed 1320-174E00 which were the early fitment (and they mushroom/recess in to the head) and 1320-151E10 which are OK but I thought the fiscal size of the 2 valves was identical.
Length [mm]89
Valve stem diameter [mm]6
Valve Head Diameter [mm]34,1
Valve Seat Angle [°]45
Can anyone confirm or deny this?