Which way to fit the flywheel on 4.0 V8

Hello All, I have had a year of blown heads on my 4.0 V8 Thor engine so decided I couldn't face doing another head change, and so I decided to swap the whole lump out.

I pulled the old engine out leaving the gearbox in place, removed the flywheel from the old engine and placed it onto the new one in the same position as I had taken it off. Reassembled the entire engine back into the car. and have now been rewarded with an engine that will not start. The earths have been checked all OK, there is spark to all the cylinders, fuel to all the cylinders.

The only explanation that anyone has been able to come up with is that the flywheel is out so effectively the nib on the flywheel is passing the crankshaft sensor at the wrong time for the cylinder needing to fire.

So my question is how the hell do you know which way the flywheel should be attached. There are four bolts in the centre of this flywheel to attach it to the engine this allows for it to be attached in any of four ways.
My theory to solve this is figure out which cylinder should fire first, measure the depth from sparkplug hole to piston head. And turn the engine until that cylinder is as high in the chamber as it can be. Then mount the flywheel so that the nib is as close to the crank sensor as will be allowed by the alignment of the four bolt holes.
Is this a sound theory anyone or am I completely barking up the wrong tree?
Someone please tell me how you should know which way round they are positioned.
Thanks all.

If you have spark and fuel then it seems likely that it is timing related (not much else!) Don't know much about these engines but with any electronic system there will be something that tells the system when to spark for which cylinder. The set point is most likely TDC on cylinder 1 as you have deduced.

There should be an explanation in the workshop manual which is available on line. Finding TDC is relatively easy with an old spark plug and a bit of bar welded in the end slightly longer than the distance at TDC. Bring the engine up to TDC clockwise and mark on the flywheel. Take the engine backwards and bring it up to the stop and mark the flywheel. Halfway between the two marks is TDC.