Bolt on turbo?

[Ruan]

Nope, they arent the same engines..

different (square) ports, few other subtle differences.. no easily accessible oil feed or return pipes for the turbo, cooling is a little different if i am not mistaken (i might be)

They are the same, the square ports are only on *VERY* early XUD9s out of 305s, some very early 205s, Citroen Visas etc.

The cylinder head is the same casting - however valves are different, rods are different, pump is different, no return for the turbo oil drain, manifolds different - not worth it.

Just get a turbo engine and it bolts straight in. Vastly easier.