what is the difference between BKP & BKD engines

[barry.d]

I have had the oil pump disaster happen with my 2006 b6 passat, it has a BKP engine fitted, I have been looking for a second hand engine but the only BKP engines available are very expensive, making it not worth doing as the car has done over 140k and is fairly tatty, I have seen more BKD engines available at a lower cost, both are 140hp pd engines, anyone know what the differences are.
Thanks

[barry.d]

not to worry I have now sent my crank to be machined & I will rebuild the bottom end of the original engine, it already has a gear driven ballance shaft & a new pump drive spindle fits fairly snug into the shaft so hopefully I won't need to spend out on a new ballance shaft module.
Thanks for reading
Barry d