So i recently converted (With plenty of assistance from Friends) my 200B from Auto to Manual.
And i know this to be the same for 240K's
If you get the correct sized Gearbox - Stumpy or Long you can use the original tail shaft.
Minor modification to the Auto Crossmember in the 200B got the Box in.
Buy this Kit - for the Master, Slave & Line (it works for 200B/1600 & 240k)
http://www.datsport.com/hydraulic-clutc ... e-kit.html
Datsport should be able to advise if it will fit your car.
This Wiki for a 1200 is super helpful
http://datsun1200.com/modules/mediawiki ... conversion
Nissan still stock the Pilot Bearing for the L Series (Actually they still stock heaps of bits