Hi,

You're half right, should be a straight swap (perhaps a mod on water & fuel
pipes depending on year of the TD engine). However, keep in mind that 205TDs
had GTi 1.6 drivetrains, to handle the power of the lump. Having 78HP on a
std Diesel chassis & 155/70/13 tyres may be hard to drive, especially on the
wet.

Regards,
G.T ('93 Junior D)
g.t6@worldonline.fr
205 Diesel & turbo-Diesel : http://205d.fr.st

Do you need a new fuel tank? You may also have to run in a fuel return
pipe from the pump to the fuel tank and doubtless some of the wiring
in the engine bay will need to be doctored. It's also worth checking
if you need to uprate the front discs and the front suspension legs as
the diesel lump is likely to be a lot heavier. Almost certainly you
will have to run new brake pipes from the vacuum pump as the existing
ones that run from the servo are unlikely to fit. On the question of
brakes, is the brake pedal connection different on a diesel to a
petrol?

The lump will almost certainly drop straight in, although may ned
different engine mountings, but there are quite a few other points to
consider as above - another one springs to mind - are the radiators
the same or interchangeable?