He's definitely an Fe/Ti user, and I think FeNi would be my estimate.
In interviews of him he's got that Ti neutralization/halting, meticulous hands and warm pushes, per example here: (feel free to jump somewhere in the middle of the vid to skip the intro)
His eyes are very difficult to tell for sure because all the footage I see of him is of him old, where the skin sags around the eyes making it hard to see what's really happening. And older people do blink more often than younger folk but this isn't necessarily due to Si. And interviews of him younger are a slight bit blurry, but Fe-lead seems clearest. He reminds me a lot of FeNi Neil DeGrasse Tyson. They've both got that assertive Fe pushyness.
I agree on Fe/Ni. One thing about Carlin that really stands out are the hilarious facial animations he does for effect. Oprah Winfrey does this as well, as does Bill Cosby. Where do clownishly animated facial expressions fit into CT, if they do at all?