Will the 70-78 doors be a direct bolt on for my 72 240?

they should be. the body was unchanged, but the only problem you MIGHT encounter would be the latching mechanism

You will defintiely encounter problems with the latching mechanisms. Interior panels and arm rests will be different as well

Do a search on the site and you will find lots of info on when the latching sytem changed.

IIRC, Basically it is 240 - early (75) 280Z doors will interchange

FOr the 280...the latches match for 75 & 76 these are the early style....77-78 have differant latches. I can check the 260 ahen I get home.