I just recently took a 2002 S-Type 4.0 engine block (AJ28) and bolted the AJ27 heads, oil structural sump and all the ancillary parts to fit into a 2000 XJ8L with a seized engine.(I traded work for the car knowing it had a bad engine)

It starts and runs fine. (I just converted it to AJ27, replaced what was different)

The later engines should have the Morse style timing components and cast-in iron liners but as long as you take the engine as a WHOLE, it will run fine.

Just be aware that if you buy some internal engine parts in the future, it would be better to state the model year of the engine rather than the MY of the chassis.

I hope this clears up the confusion.

I believe I have one. Let me look

as a new member.I have been a jag fanatic for 25 years . I own a 1991 xj6 150543 miles a 2000 xj8 85500 miles 2000 xj8 129000 miles a 2002 xkr convertible supercharged look forward to posting soon thanks