What's wrong with yours? A stripped spark plug hole can be heli-coiled and a warped one can be surface ground, if it's not too bad and you knoe a friendly machine shop.
This is the item no of a '75 head on fleabay 380184858703. Should work, but check with shop.evinrude.com first to make sure it is the same as yours.
Thanks, I seen that one, Just thought with shipping it was quite expensive for one of them. they usually go for like $20.00 on there. Of course until I need one.