Help! My 260/240Z manual says to torque the side flange bolts on the differential to 40 ft-lb. I tried that and just snapped one off at 20 ft-lbs. should the torque really be 40 IN-LBS?

40 ft-lb is correct. If the bolt broke at ft-lb the bolt was bad. The bolts are large enough to handle 40 ft-lb easily.

I snapped one of these bolts as well.. After double-checking the manual thinking I misread the torque value, it was clear there was an error made in printing. I certainly wasn't going to snap two of them, so mine are hand tightened to what felt about right. Probably not the best solution but I don't abuse or expect much from my Z so I figure it'll probably be ok. The bad bolt theory is a stretch but then again I'm no metallurgist.

I snapped one of these bolts as well.. After double-checking the manual thinking I misread the torque value, it was clear there was an error made in printing. I certainly wasn't going to snap two of them, so mine are hand tightened to what felt about right. Probably not the best solution but I don't abuse or expect much from my Z so I figure it'll probably be ok. The bad bolt theory is a stretch but then again I'm no metallurgist.

Careful with tightening to what feels right. I did that the first time around and had a strong driveline vibration from loose driveshaft bolts. The second time around I still didn't use a torque wrench, but tightened them as much as I could with an open end wrench. All is good now.