A great deal of the stuff in the 73 books are the same as 74. Take the wiring with a bit of salt, and there might be changes in some of the smog doo dads. But mechanical, front end, brakes, etc all same as 73
I gotta tell ya though, you're always preaching FSM's and after buying mine, it's very important. I can do "most" things on my car with the aid of folks on here, and 40 years of playing with them has certainly taught me a lot. But the FSM is hands down way better than a Chiltons, Haynes etc. I was amazed at the difference, I have both that we have grabbed at yard sales for 50 cents or a buck. I usually grab them when I see them just to have them..
I bought my FSM specific to year, because there are some things that escape me, like wiring. Also the book has all of the torque specs and anything else one needs to work on these old girls.