how can you tell if the engine you have has a centre thrust crank or a rear thrusted crank without opening it up?

 

As a rule of thumb and if the engine hasnt been out/rebuilt in the past,
Version 1~4 Centre thrust blocks will have a 4 bolt bell housing (2 bolts,2 studs) and Version 5 onwards rear thrust blocks will have a 6 bolt bell housing (4 bolts,2 studs).


Mick