Standard 8 and 10 engines were sidevalves, however my understanding is Morgan converted the engine to overhead valves and stuck a pretty rocker cover on with the Morgan script...then became the standard special....also used in the Triumph Mayflower prototype...

engine start of standard special see video here


Morgans 1934 MX, 1947 Series 1, 1956 +4 TR4, 2000 +4 T16
Triumph Herald 1969 13/60
Morris 1970