You can fit 2.5 petrol, 2.5 nad, 2.5td, 200tdi, 300tdi from a defender and with a little extra work a 200tdi or 300tdi from a disco, None of these engine require a conversion plate or the engine mountings modifying.. They just bolt in, i put a 200TDI in my swb series landi, it only took a night to remove the old 2.25d and fit the 200TDI in all bolted up, which just left a few old bits to tie up.