All of the blocks are the same. again and again. The main difference is the front cover and timing set between a Gems and Bosch. You can program an ECU on a D2 to run a 4.6, so you can reverse on an 03-04. The heads are all the same with the exception of secondary air. You have to run secondary air on 03-04. That is the only problem with putting a P-38 4.6 in a disco (and plugging an oil port on the front cover).

What happened to your engine? overheat or oil starvation? If just your block is toast, you CAN take a bare 4.0 block, swap you internals and heads, and be back on the road. When I say internals, I mean everything that will come off. I have not checked crank clearance on the botom of the liners personally, so this is not personal knowledge. Hopefully soon it will be...

 

let us know what you find out in terms of price, warranty, etc.

 

Actually, I have been told by 2 shops, that you can, with the right scanner, go into the ECU and set it to a 4.o setting.