Will a 2.5tdi engine bolt to a 1.9tdi box

As title
Currently have a AFN tdi which has head gasket issues
But I’ve got a 2.5tdi and thinking if poss will this bolt onto my 1.9tdi box think the box is DUK code.
Not worried about the electrics etc just would like to know if it will fit and if the ratios are ok for the 2.5 also clutch and flywheel.
Thanks

To my knowledge the engine and transmission will bolt together if you are referring to a 2.5L V6 TDI.

(The 2.5L inline five is different and would not bolt to that trans AFAIK, but since you are posting in this sub-forum and say you have an AFN now, I assume this is a B5 platform car so the V6 is what you could consider.) The gas V6 engines came attached to similar 012 transmissions so the diesel V6 probably will bolt up as well, although from what I have seen the V6 TDI never was sold from the factory with the 012.

The ratios would be good enough. Don't know what you'd need to use for a clutch and flywheel, might be able to fit the gas V6 stuff but both that and the trans itself would probably be limited on torque capacity compared to the 6spd trans and larger clutches the V6 TDI engines were originally sold with.

I think the 2.5 V6 would be a neat engine to have but headgaskets are a piece of cake to change on the old VE 4 cylinder TDI engines. Would be much less work to fix your AFN than swap. If you did want a V6 TDI, probably easiest to fix and sell your AFN car and just buy a factory built V6 TDI Passat or Audi instead, since luckily for you, you can buy those where you are.

Thanks for your reply D24TDI
My vehicle is actually a T3 Coachbuilt with a flipped gearbox.
My dilemma is the AFN is a high mileage engine and the v6 has only 80k.
I’ve also been considering a 3.0v6 gas engine due to diesels getting banned within UK cities but again my knowledge on the gearbox’s are limited.
Would you know if my current DUK box ratios would work well with a gas engine?or a Porsche Boxster gearbox would be strong enough to haul my T3? As I’m aware there used on such vehicles conversions?
Thanks
Mark

The v6 would probably enjoy the duk gearing and net better mpgs than its gasser transmission. Im running a v6 transmission on my 2.0 tdi passat. In each gear the gasser transmission is a about 300 more rpms.

You're not drag racing so I'd bet the longer gears would not be noticeable, I'd also bet it would feel quicker anyway with the broader torque band of the gas engine.

That’s got me on the classifieds for a donor ��
If I can future proof it with the 3.0 v6 gas engine then I’ll take that route not sure on flywheel or clutch to use???
Also if anyone has any info on the Boxster gearbox on its capability of hauling such a heavy vehicle as I’ve got a DVY in the shed I could use.
But huge thanks so far guys.

The duk will bolt to my 2.0 tdi. My dvz from the v6 bolts to my tdi, the dvz came factory to the donor v6 1998 b5 passat. So, you would use the stock or stock fitting v6 clutch and flyweel. The throw out bearings are the same. Some transmissions need a little of the inner bell hosing ground a bit to fit 240mm clutch/flyweels. Not all but some and i think the v6 is a 240mm. We're talking a few thousands of an inch with a side grinder.