If my video is under 70 min., I usually use a CBR of 8,000.
Anything over and I reach for my bitrate calculator.
In your case (1 hr. 41 min.), I get a CBR of 5,700 or VBR (Min., Avg., Max.) values of 3,400, 5,700, 9,600. I stick to a Max of 8,000 so I substitute this for the 9,600 value.