I know that the 4.6L engine was introduced to the Disco in '03. From what I've read, Land Rover used another vendor to provide these engines around the same time, hence the machining problems that cause oil pump issues for the 03s and, in some cases, the '04s.

I've been searching for '04 Disco engines only when it comes time to replace my '03's engine. Those are a tad too expensive for my taste.

Now, I'm wondering if I can also widen my search to low mileage '99-'02 P38 Range Rover engines as well?

What about Jaguar?

So long as I get a Bosch engine with secondary air, are there any concerns about going this route?

 

As long as you don't change anything with the emissions system you should be fine swapping in any 4.6 you find.

 

Was just checking out AB.

It looks like the oil pump and front cover might be different. Other than that it looks ok.

 

As far as I know all Bosch engines used the same front cover and oil pump regardless of which Rover it was in. Rover did make a GEMS version of the 4.6 also.