This engine is absolutely beautiful and fantastic.
The machning is really good.
Some details could be improved :
Mounting instruction.
The section about the oil and water line is really poor.
The piston rings orientation could be also more clearer and also on the rods you have a small lubrification hole.
Take care to put in in the center of the engine (to get oil from camshaft)
2 threads in the oil pan is not in the good size (M2 instead of 2.5)
The head gasket is also not perfect. Had to cut a little bit the hole where pushrods get through (most of them are touching the gasket and the valves doesn't close easily)
In the cylinder heads, they should add a lillte machining under the 4 long screws because the surface is not parallel of the bottom of the screw and they are note sitting properrly
And for the complete set with water cooling, you have no instruction how to connect the second extra tank ( for fuel but no tube in or for coolant)