Hello all, first post and all that, so bear with me.
This thread caught my attention, as I am also looking into getting a LR in SL. I have a Modified Ex-Mil LightWeight over here in the UK. Tried to look into exporting it "home" but it aint gonna happen on a 1991 reg plate (yes, I know Lightweights stopped being produced by 1984, but it is heavily modified..)
Can you expand on why you think the engine doesnt match the diffs? Does the engine over rev or does it rev too low (labour)for particular speeds?
I assume this is a LR 109, not a 110 - a Series 3?
Installing differentials from different Land Rovers into the axle casings is considered pretty easy. And bits easily found in the UK, if you are based here. Considering you might have 30Kg baggage limits, I can see potential!!
Warmest Regards