@Ben_W i have done this coversion, however it is in prototype stage at the moment and not yet passed an MOT.
It does work though and works quite well.
You need the M44 engine,
Coil pack with leads,
Manifolds,
Exhaust,
Clutch and flywheel,
Cover plate between box and bloc,
Rubber intake pipe,
Throttle cable and linkages,
Plumbing from from the donor car.
I didn't think I'd need the throttle cable etc but you definitely do.
Now from your M43 you will need
Starter,
Alternator,
Air flow meter,
All the sensors as you will need to swap them as they have different connectors. Sump as the later m43s have an oil level sensor in there.
Ping sensors,
2 wires need extending and the cam position sensor needs modification.
You can't use the hall effect sensor that comes on the M44 but the one from the M43 is too long. What you need to do is pack out the sensor i think 7.5mm. I have it written down somewhere. It took alot of working out. For the test it was a bit of pipe but I'm having a proper adapter made now it works just for neatness.
You will also need to weld another lambda sensor boss on the exhaust too as later models have 2.
The only outstanding connection is the one that went to the thermostat on the M43.
I haven't connected the secondary air injection yet either as that will require parts from the Californian model. Parts are all on eBay and I'll get them if doesn't pass emmisions. The parts are in the car i just need a Californian exhaust manifold and a longer hose from the air pump.
Hope this helps
