Mgb engine brexit

Welp.  I was driving around , everything going perfectly, when there was a clattering from the engine compartment.  Sounded like slapping a belt across a flat surface.
  That happened a couple times then the engine lost about 76 horsepower and died on the side of the road.
Thinking the fan belt came off, i popped the hood. Everything was where it should be.   Got it restarted running  rough. Not enough to pull itself in 1st gear.
  Called a buddy for a tow.

Excellent mpgs.  V8 power!

Note the pushrod vs rocker orientation.  After putting it back in place the valves were re gapped.  Couldn't get it running right without gas straight into the carbs, and it wont idle.
  Soooo the head gas to come off. To see whats up.