crank pully bolt torque setting?

[luke70]

What should the crank pully bolt be torqued to? (I think engine is a mid 70's 3.4) Haynes doesn't say

Where is the engine number located and how do I decode it to find what model it was fitted to?

Is there a way of ID ing the type of head fitted? I have a casting number in the plug valley closest to the bulkhead, on another forum it said this was only on pre67 cars. Anyone got that sort of info?

thanks fellas

[alec2824]

The workshop manual for the series 2 XJ6 gives the torque setting for the crankshaft as 125-150 pounds feet or 17.3-20.7 kgf/m.It also says that it is a 3/4in UNF BOLT.