I don't have any pics of the underside of the 604, but this is one of a 505 which is essentially the same (in fact the front cross member, suspension and steering is all interchangeable.
As you can see where the steering column meets the rack it is extremely close to the bell housing.
On four cylinder Peugeots they mounted the starter motor up high, kind of near where the injection pump is on the Audi TDI.
On V6 Peugeots the starter motor is much lower hence the different bell housing for left/right hand drive