As above have posted, greater aperture will show much more. That being said, if you're just curious like I am, the 76mm masked down does deliver a tiny bit better performance over the 60mm. I believe this is because the edges of a lens are usually not as good as the center and the 76mm with those edges masked out delivers the best part of the lens. This might be giving it a bit of an advantage over the 60mm. Of course, you might get different results comparing different scopes than what I used. Maybe, my 76mm was just simply much better than the 60mm I was using for the comparison.
If you want to improve the performance of your 76mm you can do things like upgrade the focuser to 1.25" and use high quality eyepieces/diagonal, use a Takahashi 1.6x Extender Q (makes a surprising difference, but then you're stuck using really high magnifications), and depending on the correction of your lens, sometimes using a prism instead of a mirror diagonal will produce better color correction due to some canceling out of the CA.
Also, flocking the tube/focuser and using flat black paint on any shiny reflective surfaces helps. Making sure the baffles are correctly placed is something else you can try. Adding a better finder or some type of red dot/reflex finder. Getting tube rings from Orion, adding a dovetail, and putting it on a better mount is another popular option. There are filters one can get which are supposed to help with CA if that's a big deal to you. At almost f/16, I have never seen a need to do that, but everyone is different.
I am sure the experts here will have lots more great advice on improving your 76mm.