Aiwa CS 600 tape swap query

[Stuckinthe80s]

I am intending to replace the dud tape deck from my CS600 with one from a donor machine.
Should I retain the original heads or just swap the complete unit?

 

[Hisrudeness]

You’ve got a donor CS-600 tape deck?

 

[Stuckinthe80s]

Hopefully, just won an auction for a CS300.
Im led to believe it has the same mechanism.