1993 range rover classic ECU option?

[93 elephant]

my dad is about to give me his old 93 range rover classic (4.2) so that i have something to tow my race car with.  problem is that it's been in a barn somewhere for a couple of years because it just won't run properly.  I have a few ideas for the cause but in case I lose my sanity and do not get it sorted, i'm thinking about backup plans.

I was at the local scrapyard the other day and noticed that there's a 2000 land rover discovery 4.6 there.  the prices at this yard are quite good.  question is, can I run the 4.2 on the bosch management designed for the 4.6?  what would i need?  from what I estimate, the swap wouldn't cost more than $200...but that's based on guessing the complonents required, i may need more of course.

at the moment i believe i would need:

the ecu and harness
maybe it's interface with the cluster and possibly the cluster?
all the sensors
post cat o2 sensors
maybe the intake manifold and plumbing?

am i mising something in that list?  will the motronic system say wtf to the smaller engine?

thanks

[avbates]

From recolection, the 4.6 also has coil packs and igniytion pickup.  the 4.2 uses a traditional distributor
Regards
Tony