I've considered going 3" but not sure if it'll be truly worth my while N/A
Honestly, you have the cubes to potentially use the 3in but you dont necessarily need it. I ran 2.5in for a long time with the 410/blower combo and made very good power. Was it ideal? No, but it can work. The added benefit is it's quieter to boot. Especially if you go with chambered muffs.
If you do run 3in and noise is a concern to you, run them out the back with chambered mufflers. Don't dump em. Makes a huge difference for in cabin noise.
I have thought about going to 3in mac pro chambers. I like the sound better when the motor is off the blower. With the race bullets the car sounds odd to me. However, once the motor is up on the blower its rediculous with the bullets...