johnt

I am replacing doors throughout my house( putting slab doors in existing frames) with a porter cable router and hinge template that my Dad used 50 years ago.
With these 2 tools I can cut perfect mortises for 3 1/2" hinges with 1/4" radius but unfortunately I need a 5/8" radius for my hinges.
So my question is: what do I need to get that radius... a different guide bushing?
If I use a larger bushing, won't I end up with a smaller mortise?
Here are the measurements on the one I am using :
OD 0.8" (20.3mm)
ID 0.6" (15.6mm)
1/2" mortising bit
Thanks for any help,
John