Figure out what is there and then we can figure out what is needed.
Right off the bat, the alternator mounting is missing a spacer.
A longer bolt will be needed along with the spacer.
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Some of the things that effect the belt alignment is the timing cover, water pump, and pulleys.
Also the alternator mounting brackets.
The radiator top is correct for '69
Look at the water pump inlet. If it points toward the fuel pump, its '70 up. My guess is that is what is on there - most aluminum pumps are. We won't know which impeller it has, but that's a second issue. It relates the proper pulleys to choose. So it will come up again.
The fan looks to me like a later fan.
Pulley I'm not sure about.
The side of the engine block will have a casting date. I don't think that's important. What is important in terms of alignment can be the water pump, the timing cover, matching pulleys.
Good news on the alternator pulley is that's a factroy pulley not one of the new pieces of junk.