AAZ swap

Nachdem ich nun auch das Problem mit der Kurbelwellenschraube hatte und sich der Motor verabschiedet hat, will ich den Motor tauschen. Okay, here's the translation:

Now, my questions:
Old AAZ engine, Passat 35i, 12/91, 55 kW at 4400 rpm.
New engine from a Golf 3, manufactured in 5/99, also an AAZ model with 55 kW, but with a power output of 4200 RPM.

Okay, so we're missing 200 RPM, and that will affect the final speed. Should the transmission also be modified accordingly (e.g., with a different gearbox), or should the ESP be adjusted?

Regards,
hood

Hello,
Okay, one more question:
Is it possible to create an AAZ engine by using a different bare engine block (ABL, 1X, 1Y, OKM) and using the components from my defective AAZ engine? Or are there differences between the different bare engine blocks?

Hello,

I know the specifications of naturally aspirated diesel engines like the 1X and 1Y by heart; it's no problem! They also have piston cooling, but unfortunately, the oil return from the turbo doesn't have a connection on the engine block (usually -> you can use an oil pan from a Golf 2 with a suitable return line, or you can fabricate one yourself). Furthermore, it is highly recommended to replace the cylinder head gasket with a multi-layer metal gasket if it hasn't already been installed.
There are also differences in the piston bolts; the AAZ engine, like the TDI, uses 26mm bolts, while the 1Y and 1X engines use 24mm bolts, but I don't see that as a problem; they are perfectly durable! Also, the oil connection doesn't quite fit on the oil filter flange, as a threaded hole of M12x1.5 is needed for the pipe (oil supply to the turbo), but only a thread of M10x1.0 is available.

Regards