very rare engine in the states. thats an original E50, first style case and cylinder/head. the whole engine is different. although im pretty sure that by 1974 they had changed the engine to the modern style. the only years ive seen this engine on were like 1969-71 maxis...are you sure its a 1974? does the engine number match the frame number? i always wanted one of these original E50s.
here it is on a beautiful 1969 maxi: