Well Wokri ;
That all depends upon whom you ask.....
My Chevy dealer training taught me to replace worn out main bearing shells in full pressure engines by loosening all the bearing caps them removing one and inserting a large cotter pin you previously banged with a hammer to deform the loop head into a "T" shape ~ the flattened 'T' pushes the old bearing half shell out as you rotate the crankshaft, you'd want to turn the crankshaft so the end of the bearing shell with the tang on it comes out first .
This used to be part and parcel of routine overhaul service and no, the engine doesn't come out nor did one bore the tapered cylinders unless they exceeded .014" taper (!) .
At the same time you'd replace the rod bearings and touch up the valves, amazingly this made a noisy smoky rattly old engine run like new again and was done by every gas station Mechanic back in the day and not a few Farmers too .
Before you get all excited, take a moment to LOOK at the bearings, main and rod, then decide .
If the engine runs well and doesn't smoke /knock, just leaks a bit of oil out the back, put a diaper on it like you're forced to do with oldtimers in Germany....
If you decide to do this freshen up ask me or look for my older posts, it's all pretty simple, easier IMO than rebuilding an air cooled VW engine .
