Yep that is a 300Tdi conversion for sure. As said above, it is the sepentine belt that gives it away. 300tdi engines were first fitted into defenders in the mid 1990s. A 1988 90/110 would have most likley been fitted with a 19J 2.5 Diesel Turbo. The Chassis number will confirm this. The 8th letter will tell you what was originally fitted.B = 2.5 turbo diesel, C= 2.5 NA diesel, D = 2.5 Petrol and V = V8 petrol.
It looks like from your picture that who ever did the conversion paid attention to the little details rather than just chucking it in. The 300Tdi sits further back in the engine bay when fixed to the LT77 gearbox and you have a lot of space between the front of the engine and the radiator, so they have properly extended the coolant, oil and intercooler pipework to reach using parts from what look like Steve Parker. The airfilter is off a discovery, so this enigne was more than likely originally fitted to a disco (not a problem with doing that as 300 Tdis were the same in disco and defender). It also looks like they blanked off the EGR which is a wise move. Does the temperature gauge work properly (ie the needle sits where it should do) because the original gauge will read high if you don't change the sender in a 300. Again Steve Parker sell a sender for 300Tdi conversions to make the original gauge read correctly.
