All yrs will interchange with no problem whatsoever. It will just be a matter of how far u will be able to open the hood.
note - early hinges that "fully open the hood" will allow u to pull the eng and trans together, WITHOUT REMOVING THE HOOD.
later hinges will not open far enough to do that.
Year it changed "may" be 69, based on my 68 with a hood that gets up higher than my 69 truck.
Plastic trucks suck...
Iron trucks rule...