I have just tried to fit a fat case EA71 to my 1974 sedan. Unfortunately this is not the straight forward swap I hoped it would be! The later fat case engine has a pilot bearing pressed into the flywheel (like EA81 engines) while the EA63 engine uses a small needle roller bearing that is pressed into the end of the crankshaft. This means the EA63 4 speed gearbox is not compatible with the fat case engine as the bearing arrangement means the engine and gearbox do not join up. it does fit together without the bearing in the flywheel but unfortunately it is not possible to fit a needle roller bearing into the fat case crankshaft as the hole is too large. I am using the EA63 bellhousing and clutch because I would like to keep the original 4 speed.
So my question to the board is (before I remove another engine!), does the early EA71 engine with external water crossover use the small needle roller bearing in the crankshaft like the EA63? My thinking is that it does but I would like to have this confirmed before I make another attempt.