From the serial number 93xxxx the engine dates from March 1969, in August of that year they stopped stamping the serial number into the crankcase and instead put it on the cylinder cooling baffle (not fitted on this engine), which are often taken off & go missing.
Very nice engine by the way, you've reminded me I need to fit the Octura carb & exhaust to mine, it's not the V8 exhaust though.
David