I have a AZU model A Fourgonnette with a 6volt 425 (18cv) engine and old style cardan drive shafts. I want to swap out to a 602cc AK2 (engine M28/1). I guess I need a different gear box. Would like to keep drum brakes all round using Dot 4 liquid.

Obviously change from 6 - 12 volt, and would like proper 2cv joints.

Need new hubs to fit drive shaft splines.
Need to think about heater ducts etc

What else must I think about (apart from not doing it), and is there anything on the web I should look at ?

Gone and done it - just bought a matching (I hope 200mm drum gearbox) Still need advice if there is any.

<sigh> There goes another one.

Wouldn't it be easier to sell the old van and buy a '70s one?

I use the van quite a lot, have brought it back from the brink of death at the scrapyard - and after having it on the road for 3 years decided that I deserve a bit more pulling power up the local hills. Tramping around in 2nd gear with a conger of moderns behind you is fun to start with, but it wears off after a bit.
Anyway, for those who want to swapout, CATS Citroen site has a bunch of usefull information - thanks Dennis.

Agree, why butcher such a unique van for ''more speed (torque)'' Keep it original and buy a modern van

It really fucks me off when people write things like this. What you want to do to your van is down to you and making your van pleasurable to drive for you is what you want to do, so do it and enjoy the results. Since when was 2cving about leaving the whole car exactly as it left the factory? What a boring place a 2cv meeting would be if we all did that.

+1

Conversely, if everyone fitted a 602 there would be no originals left, but maybe that doesn't matter. It would be a shame to lose all the originals.

Horses for courses & all that, but I'm sure there are plenty of people out there who realise the value & rarity of their vehicles. Plus, things can be put back to original sometimes.
Don't see why people should be criticised for doing what they want with their property, though. Shite or awesome as it might be.

If somebody told me not to 602 my car it'd just make me want to do it more.