In the hard copy manuals that I have that torque setting is for the drive pulley bolts and not the tensioner/idler bolts. However, that torque range covers many of the bolts/nuts all over the car so I would not be surprised that it will be in the approximate region for the tensioner/idler too.
243 is medium strength so will be fine. I tend to use thread lock a fair amount where oiled threads are not specified. Either that or copper grease if I know I'll have to take the part off from time to time, for instance the screws on top of the air box. Just be careful using thread lock near plastics as some are affected by it. There is a thread lock for plastics but not commonly used.
Last edited by armoore; 06-04-10 at 15:36.