Angle cut.
Basically, chop the lower stock tang off the Hunter receiver, do some math, that'll tell you how much of the Galil rear receiver stub you need to chop and just follow the angle of the Hunter receiver, it'll give you what you need if you pay attention.
I've seen Hunter conversions where they "chopped" the receiver to make the welding a straight "up/down" thing, but then you have a nasty big weld at the rear of the rifle and the receiver, even welded, isn't "intact"
Here's a pic of one I had done, if you look closely you can see how the weld was done.
Good luck with your project, it's work, but it is worth it when you finish.

As Galil AR.


Rifle how it is now, I just "had" to go the Valmet way!