I "think" some did and some didn't. My 71 already had them and had never been apart before I got it. Maybe someone with more experience can chime in. I was thinking 71 or 72 for sure (both used 346's) had the hardened seats.

They are not expensive to have put in if need be or you could go with 452's which, for sure, would have them.

Bottom line for my case was that I read way too many magazines with all the latest high end build ups and it actually set me back because I wanted to build what I had read. I should have stayed with my set goals, maintained a realistic budget, etc, and I would have saved money and enjoyed the car FAR earlier than before.

Your car is an awesome find and looks as though it is very complete. If the shortblock doesn't have many miles on it, you may just want to swap out a set of fresh heads, restore the carb, then move on to the rest of the drivetrain.

You could easily spend 15-25K restoring a car nut by nut and bolt by bolt, but then your scared to drive it, thrash on it, and tearing up your hard earned investment/toy.

If you bring a set of heads down to 78cc's or find a good used set of 516's, you can up your compression without touching the shortblock. I think you may be surprised how well a stock 383/4spd will run once its tuned properly and everything else in the drivetrain is up to par. It might not be a 13 sec. car stock, but it doen't take much to get into the 13's with a 383 HP and a few mild performance enhancements.

Focus on street use, not racing. As there where you'll be enjoying the car the most.