I know the early 260z had front disc brakes and rear drum brakes. I have a 240z parts car and a 260z I'm trying to get running. Would it be possible to swap the front discs to replace my rear drum brakes on the 260z? Or would that be a bad idea? Would that even work?

Bad and dangerous idea.No it won't work.

If you want disc brakes on the rear, then you need to look at getting the rear set-up from a 280ZX. (OMG! I said the forbidden word! :tapemouth )

Try doing a search on this site. I'm not sure if there is a write up here or not. I'm pretty sure there is one at www.zhome.com There are also very good write ups around the net, you just have to do a little searching. This might be a little involved as I believe you also have to swap part of the half shaftes because of the different stub axles from the 280ZX.

Good luck on the project, though.