Apologies in advance if I'm covering old ground here, but I'm hoping your collective experience can guide me on the next step.

The Symptoms: My 4.0 94K 2000 Bosch Supplementary Air Discovery II motor had a chronic cylinder 6 misfire. Compression test showed #6 at 50% of other cylinders. Green coolant had yellow floating scum like shaving cream. Smells of gas.

The Forensics: Had that cylinder head pressure tested by reputable local machine shop. They tell me it tests OK. Inescapable conclusion seems to be a bad block/sleeve.

Questions:
Is this the correct/only interpretation of the symptoms?
Is this block a goner (unless the sleeves are replaced)?
Are there any other in-place tests I should/can do before writing off the block?

I can pick up a cheap Range Rover 4.6 from a rollover. Reading in the forum it appears that my 2000 block and a Range Rover 4.6 block are completely interchangeable. Are there any years that are exceptions?
Is a Range Rover 4.6 a complete drop in swap for a 2000 Discovery II? i.e. Identical wiring, hoses, exhaust connections, the whole tamale, or are there years that don't work with the 2000 Discovery? If the interchangeability is not absolutely 100%, how much adaptation is required?

Many thanks in advance for your guidance.
Andrew

 

There are two p38 range rover 4.6L engines. One with GEMS fuel injection, and one with Bosch Motronic fuel injection. You'll want the bosch style. If the P38 engine is Bosch with SAI, it will bolt right in. If no SAI, you'll need to use your heads.

 

That broadens the field a little.