Imp 50 is the name given to this year, being the 50th anniversary of the Hillman Imp, the first car having been released May 3rd 1963, lots will be happening around this date in Coventry,UK.
www.theimpclub.co.uk check the link to see what the Imp Club has planed for the event.
The carrier design is still basically that of the 1963 Mk1 Imp, its just relieved where the higher camshaft lobes stick out. The valve lift goes from the standard 0.290" to 0.360" and the top of the cam lobes are near flat to allow the valves to stay open longer. A dial gauge has to be used to set the timing on this type of Rootes Competitions camshaft.
Look at the base of the carrier, its just possible to see a 1mm thick stainless steel spacer shim, the sport 180 series head was bowed and required skimming on both faces, the shim made up for the metal removed from the top face. Both the camshaft and new followers and the shim came from a supplier in England.