hifi engine

Alignment of tape heads for recordings of tapes from different sources

Can anyone advise on my question ...
I have a Teac A3340S and my father has some valuable recordings made on a 4 track Grundig machine from the early 60s, possibly a TK5. Would it be an abuse to attempt to change the head height to match these tapes? Would it be easy to get it back to the original position?
Also I suppose the spacing of the tracks may be different so a different adjustment would be needed to play each track!