Possible issues fitting a 300tdi chassis to a different body?

Im on the lookout for a 300tdi defender.

One possible option is to get a 110 with a duff chassis, and a new 110 chassis from richards etc. set up for the 300tdi (i have a 300tdi from a disco, and an r380 which could be adjusted)

But is it that simple?

Are there other things that would stop me doing this?

Thanks, Julian