47cc = shorter crank - not a D
tapered head = not a C
14mm intake = not a B
40km on the jug confirms - it's an A. unsurprisingly, theyre by FAR the most common. enjoy the sachsing.
This is all in the motor differences page but there's no moving the wrist pin. the pin height is different on A/B vs D/C pistons. But as long as the piston and jug are matched it works. you can put an A/B piston and cylinder on a D crank, and you can put a D piston and cylinder on an A crank (making it a "C"). you just can't put an A piston in a D or it'll hit the head. it's not about the stroke difference, it's just that the piston and cyl must be a matched pair.
The other holdup is the cylinder studs are a little differently placed. you can easily Dremel out the slots for the studholes to swap cylinders though, the kits and gaskets are already wider slots to accommodate either stud placement. just match the holes to the base gasket, see below