Just a FYI for getting that bolt out without jamming up the engine and not having the "removal tool" First, get almost exact or exact socket.. 33 MM seems to be perfect, 34 will work and 1 and 5/16 closer that the 34MM. (had to settle for the 1 and 5/16 from granger, apparently 32-34 MM don't exist for them)
With car not on jacks, place socket on bolt with a breaker bar that reaches the ground. orient it so breaker bar is as far clockwise as it will go and touching the ground. next, make sure car will not start by removing coil lead or something similar.. VERY INPORTANT! FINALLY, Bump the starter. and poof! bolt is loose and already coming off! let your mind and the starter do the heavy work. and if you are just taking off the pulley bolts, just place breaker bar in opposite direction to keep engine from turning while removing those smaller bolts around the main.

 

I did that on mine, too.
It was quite easy and simple.

http://jaglover.web.fc2.com/XJSmaint...ankdamper.html

When tightening, I used hardest loctite and screw in the crank bolt, and I hammered the breaker bar to tighten the bolt. I was told hammering has the same effect as an impact wrench.
Eventually I didn't lock the engine from turing during the process, I have no problem since then.
I couldn't use Bernard Embden's method on my facelift XJS, I couldn't cramp the ring gear, for there is a flywheel sensor(for Marelli ignition) and the bracket is in the way.