Yeah, you can tell this much just from what's shown in the pics...
1. That looks to be the original color paint on the engine, looking at the patina. That color was only used in 75-76.
2. Emission control devices that are present were correct for the 75-76 year, particularly the EGR that doesn't have the BPT on it.
3. Heads are clearly 6X, used only in late 75 and 76.
Beyond that, as Jeff and John suggest you need to look in those specific locations to get the casting numbers, etc.